diff --git a/src/watch.js b/src/watch.js
index 0c6dea2..48755c6 100644
--- a/src/watch.js
+++ b/src/watch.js
@@ -51,17 +51,33 @@
         var aplus = [],
         bplus = [];
 
-        if(!(typeof a == "string") && !(typeof b == "string") && !isArray(a) && !isArray(b)){
+        if(!(typeof a == "string") && !(typeof b == "string")){
 
-            for(var i in a){
-                if(b[i] === undefined){
-                    aplus.push(i);
+            if (isArray(a)) {
+                for (var i=0; i<a.length; i++) {
+                    if (b[i] === undefined) aplus.push(i);
+                }
+            } else {
+                for(var i in a){
+                    if (a.hasOwnProperty(i)) {
+                        if(b[i] === undefined) {
+                            aplus.push(i);
+                        }
+                    }
                 }
             }
 
-            for(var j in b){
-                if(a[j] === undefined){
-                    bplus.push(j);
+            if (isArray(b)) {
+                for (var j=0; j<b.length; j++) {
+                    if (a[j] === undefined) bplus.push(j);
+                }
+            } else {
+                for(var j in b){
+                    if (b.hasOwnProperty(j)) {
+                        if(a[j] === undefined) {
+                            bplus.push(j);
+                        }
+                    }
                 }
             }
         }
@@ -157,11 +173,13 @@
             }
         } else {
             for (var prop2 in obj) { //for each attribute if obj is an object
-                props.push(prop2); //put in the props
+                if (obj.hasOwnProperty(prop2)) {
+                    props.push(prop2); //put in the props
+                }
             }
         }
 
-        watchMany(obj, props, watcher, level, addNRemove); //watch all itens of the props
+        watchMany(obj, props, watcher, level, addNRemove); //watch all items of the props
 
         if (addNRemove) {
             pushToLengthSubjects(obj, "$$watchlengthsubjectroot", watcher, level);
@@ -176,7 +194,9 @@
         }
 
         for (var prop in props) { //watch each attribute of "props" if is an object
-            watchOne(obj, props[prop], watcher, level, addNRemove);
+            if (props.hasOwnProperty(prop)) {
+                watchOne(obj, props[prop], watcher, level, addNRemove);
+            }
         }
 
     };
@@ -192,15 +212,12 @@
         }
 
         if(obj[prop] != null && (level === undefined || level > 0)){
-            if(level !== undefined){
-                level--;
-            }
-            watchAll(obj[prop], watcher, level); //recursively watch all attributes of this
+            watchAll(obj[prop], watcher, level!==undefined? level-1 : level); //recursively watch all attributes of this
         }
 
-        defineWatcher(obj, prop, watcher);
+        defineWatcher(obj, prop, watcher, level);
 
-        if(addNRemove){
+        if(addNRemove && (level === undefined || level > 0)){
             pushToLengthSubjects(obj, prop, watcher, level);
         }
 
@@ -233,7 +250,9 @@
             }
         } else {
             for (var prop2 in obj) { //for each attribute if obj is an object
-                props.push(prop2); //put in the props
+                if (obj.hasOwnProperty(prop2)) {
+                    props.push(prop2); //put in the props
+                }
             }
         }
 
@@ -244,11 +263,13 @@
     var unwatchMany = function (obj, props, watcher) {
 
         for (var prop2 in props) { //watch each attribute of "props" if is an object
-            unwatchOne(obj, props[prop2], watcher);
+            if (props.hasOwnProperty(prop2)) {
+                unwatchOne(obj, props[prop2], watcher);
+            }
         }
     };
 
-    var defineWatcher = function (obj, prop, watcher) {
+    var defineWatcher = function (obj, prop, watcher, level) {
 
         var val = obj[prop];
 
@@ -262,7 +283,7 @@
             obj.watchers[prop] = [];
         }
 
-        for(var i in obj.watchers[prop]){
+        for (var i=0; i<obj.watchers[prop].length; i++) {
             if(obj.watchers[prop][i] === watcher){
                 return;
             }
@@ -281,14 +302,16 @@
             var oldval = val;
             val = newval;
 
-            if (obj[prop]){
-                watchAll(obj[prop], watcher);
+            if (level !== 0 && obj[prop]){
+                // watch sub properties
+                watchAll(obj[prop], watcher, (level===undefined)?level:level-1);
             }
 
             watchFunctions(obj, prop);
 
             if (!WatchJS.noMore){
-                if (JSON.stringify(oldval) !== JSON.stringify(newval)) {
+                //if (JSON.stringify(oldval) !== JSON.stringify(newval)) {
+                if (oldval !== newval) {
                     callWatchers(obj, prop, "set", newval, oldval);
                     WatchJS.noMore = false;
                 }
@@ -301,14 +324,14 @@
 
     var callWatchers = function (obj, prop, action, newval, oldval) {
         if (prop) {
-            for (var wr in obj.watchers[prop]) {
-                if (isInt(wr)) {
-                    obj.watchers[prop][wr].call(obj, prop, action, newval || obj[prop], oldval);
-                }
+            for (var wr=0; wr<obj.watchers[prop].length; wr++) {
+                obj.watchers[prop][wr].call(obj, prop, action, newval, oldval);
             }
         } else {
             for (var prop in obj) {//call all
-                callWatchers(obj, prop, action, newval, oldval);
+                if (obj.hasOwnProperty(prop)) {
+                    callWatchers(obj, prop, action, newval, oldval);
+                }
             }
         }
     };
@@ -340,7 +363,7 @@
     };
 
     var unwatchOne = function (obj, prop, watcher) {
-        for(var i in obj.watchers[prop]){
+        for (var i=0; i<obj.watchers[prop].length; i++) {
             var w = obj.watchers[prop][i];
 
             if(w == watcher) {
@@ -353,7 +376,7 @@
 
     var loop = function(){
 
-        for(var i in lengthsubjects){
+        for(var i=0; i<lengthsubjects.length; i++) {
 
             var subj = lengthsubjects[i];
 
@@ -377,7 +400,7 @@
             
                 if(difference.added.length || difference.removed.length){
                     if(difference.added.length){
-                        for(var j in subj.obj.watchers[subj.prop]){
+                        for (var j=0; j<subj.obj.watchers[subj.prop].length; j++) {
                             watchMany(subj.obj[subj.prop], difference.added, subj.obj.watchers[subj.prop][j], subj.level - 1, true);
                         }
                     }
@@ -414,7 +437,7 @@
 
     var removeFromLengthSubjects = function(obj, prop, watcher){
 
-        for (var i in lengthsubjects) {
+        for (var i=0; i<lengthsubjects.length; i++) {
             var subj = lengthsubjects[i];
 
             if (subj.obj == obj && subj.prop == prop && subj.watcher == watcher) {
diff --git a/src/watch.min.js b/src/watch.min.js
index 7d666ac..f2debef 100644
--- a/src/watch.min.js
+++ b/src/watch.min.js
@@ -1 +1 @@
-"use strict";(function(e){if(typeof exports==="object"){module.exports=e()}else if(typeof define==="function"&&define.amd){define(e)}else{window.WatchJS=e();window.watch=window.WatchJS.watch;window.unwatch=window.WatchJS.unwatch;window.callWatchers=window.WatchJS.callWatchers}})(function(){var e={noMore:false},t=[];var n=function(e){var t={};return e&&t.toString.call(e)=="[object Function]"};var r=function(e){return e%1===0};var i=function(e){return Object.prototype.toString.call(e)==="[object Array]"};var s=function(e,t){var n=[],r=[];if(!(typeof e=="string")&&!(typeof t=="string")&&!i(e)&&!i(t)){for(var s in e){if(!t[s]){n.push(s)}}for(var o in t){if(!e[o]){r.push(o)}}}return{added:n,removed:r}};var o=function(e){if(null==e||"object"!=typeof e){return e}var t=e.constructor();for(var n in e){t[n]=e[n]}return t};var u=function(e,t,n,r){try{Object.defineProperty(e,t,{get:n,set:r,enumerable:true,configurable:true})}catch(i){try{Object.prototype.__defineGetter__.call(e,t,n);Object.prototype.__defineSetter__.call(e,t,r)}catch(s){throw"watchJS error: browser not supported :/"}}};var a=function(e,t,n){try{Object.defineProperty(e,t,{enumerable:false,configurable:true,writable:false,value:n})}catch(r){e[t]=n}};var f=function(){if(n(arguments[1])){l.apply(this,arguments)}else if(i(arguments[1])){c.apply(this,arguments)}else{h.apply(this,arguments)}};var l=function(e,t,n,r){if(typeof e=="string"||!(e instanceof Object)&&!i(e)){return}var s=[];if(i(e)){for(var o=0;o<e.length;o++){s.push(o)}}else{for(var u in e){s.push(u)}}c(e,s,t,n,r)};var c=function(e,t,n,r,s){if(typeof e=="string"||!(e instanceof Object)&&!i(e)){return}for(var o in t){h(e,t[o],n,r,s)}};var h=function(e,t,r,s,o){if(typeof e=="string"||!(e instanceof Object)&&!i(e)){return}if(n(e[t])){return}if(e[t]!=null&&(s===undefined||s>0)){if(s!==undefined){s--}l(e[t],r,s)}m(e,t,r);if(o){x(e,t,r,s)}};var p=function(){if(n(arguments[1])){d.apply(this,arguments)}else if(i(arguments[1])){v.apply(this,arguments)}else{E.apply(this,arguments)}};var d=function(e,t){if(e instanceof String||!(e instanceof Object)&&!i(e)){return}var n=[];if(i(e)){for(var r=0;r<e.length;r++){n.push(r)}}else{for(var s in e){n.push(s)}}v(e,n,t)};var v=function(e,t,n){for(var r in t){E(e,t[r],n)}};var m=function(t,n,r){var i=t[n];w(t,n);if(!t.watchers){a(t,"watchers",{})}if(!t.watchers[n]){t.watchers[n]=[]}for(var s in t.watchers[n]){if(t.watchers[n][s]===r){return}}t.watchers[n].push(r);var o=function(){return i};var f=function(s){var o=i;i=s;if(t[n]){l(t[n],r)}w(t,n);if(!e.noMore){if(JSON.stringify(o)!==JSON.stringify(s)){g(t,n,"set",s,o);e.noMore=false}}};u(t,n,o,f)};var g=function(e,t,n,i,s){for(var o in e.watchers[t]){if(r(o)){e.watchers[t][o].call(e,t,n,i,s)}}};var y=["pop","push","reverse","shift","sort","slice","unshift"];var b=function(e,t,n,r){a(e[t],r,function(){var i=n.apply(e[t],arguments);h(e,e[t]);if(r!=="slice"){g(e,t,r,arguments)}return i})};var w=function(e,t){if(!e[t]||e[t]instanceof String||!i(e[t])){return}for(var n=y.length,r;n--;){r=y[n];b(e,t,e[t][r],r)}};var E=function(e,t,n){for(var r in e.watchers[t]){var i=e.watchers[t][r];if(i==n){e.watchers[t].splice(r,1)}}T(e,t,n)};var S=function(){for(var e in t){var n=t[e];var r=s(n.obj[n.prop],n.actual);if(r.added.length||r.removed.length){if(r.added.length){for(var i in n.obj.watchers[n.prop]){c(n.obj[n.prop],r.added,n.obj.watchers[n.prop][i],n.level-1,true)}}g(n.obj,n.prop,"differentattr",r,n.actual)}n.actual=o(n.obj[n.prop])}};var x=function(e,n,r,i){t.push({obj:e,prop:n,actual:o(e[n]),watcher:r,level:i})};var T=function(e,n,r){for(var i in t){var s=t[i];if(s.obj==e&&s.prop==n&&s.watcher==r){t.splice(i,1)}}};setInterval(S,50);e.watch=f;e.unwatch=p;e.callWatchers=g;return e})
\ No newline at end of file
+"use strict";(function(e){if(typeof exports==="object"){module.exports=e()}else if(typeof define==="function"&&define.amd){define(e)}else{window.WatchJS=e();window.watch=window.WatchJS.watch;window.unwatch=window.WatchJS.unwatch;window.callWatchers=window.WatchJS.callWatchers}})(function(){var e={noMore:false},t=[];var n=function(e){var t={};return e&&t.toString.call(e)=="[object Function]"};var r=function(e){return e%1===0};var i=function(e){return Object.prototype.toString.call(e)==="[object Array]"};var s=function(e,t){var n=[],r=[];if(!(typeof e=="string")&&!(typeof t=="string")){if(i(e)){for(var s=0;s<e.length;s++){if(t[s]===undefined)n.push(s)}}else{for(var s in e){if(e.hasOwnProperty(s)){if(t[s]===undefined){n.push(s)}}}}if(i(t)){for(var o=0;o<t.length;o++){if(e[o]===undefined)r.push(o)}}else{for(var o in t){if(t.hasOwnProperty(o)){if(e[o]===undefined){r.push(o)}}}}}return{added:n,removed:r}};var o=function(e){if(null==e||"object"!=typeof e){return e}var t=e.constructor();for(var n in e){t[n]=e[n]}return t};var u=function(e,t,n,r){try{Object.observe(e[t],function(e){r(e)})}catch(i){try{Object.defineProperty(e,t,{get:n,set:r,enumerable:true,configurable:true})}catch(s){try{Object.prototype.__defineGetter__.call(e,t,n);Object.prototype.__defineSetter__.call(e,t,r)}catch(o){throw new Error("watchJS error: browser not supported :/")}}}};var a=function(e,t,n){try{Object.defineProperty(e,t,{enumerable:false,configurable:true,writable:false,value:n})}catch(r){e[t]=n}};var f=function(){if(n(arguments[1])){l.apply(this,arguments)}else if(i(arguments[1])){c.apply(this,arguments)}else{h.apply(this,arguments)}};var l=function(e,t,n,r){if(typeof e=="string"||!(e instanceof Object)&&!i(e)){return}var s=[];if(i(e)){for(var o=0;o<e.length;o++){s.push(o)}}else{for(var u in e){if(e.hasOwnProperty(u)){s.push(u)}}}c(e,s,t,n,r);if(r){x(e,"$$watchlengthsubjectroot",t,n)}};var c=function(e,t,n,r,s){if(typeof e=="string"||!(e instanceof Object)&&!i(e)){return}for(var o in t){if(t.hasOwnProperty(o)){h(e,t[o],n,r,s)}}};var h=function(e,t,r,s,o){if(typeof e=="string"||!(e instanceof Object)&&!i(e)){return}if(n(e[t])){return}if(e[t]!=null&&(s===undefined||s>0)){l(e[t],r,s!==undefined?s-1:s)}m(e,t,r,s);if(o&&(s===undefined||s>0)){x(e,t,r,s)}};var p=function(){if(n(arguments[1])){d.apply(this,arguments)}else if(i(arguments[1])){v.apply(this,arguments)}else{E.apply(this,arguments)}};var d=function(e,t){if(e instanceof String||!(e instanceof Object)&&!i(e)){return}var n=[];if(i(e)){for(var r=0;r<e.length;r++){n.push(r)}}else{for(var s in e){if(e.hasOwnProperty(s)){n.push(s)}}}v(e,n,t)};var v=function(e,t,n){for(var r in t){if(t.hasOwnProperty(r)){E(e,t[r],n)}}};var m=function(t,n,r,i){var s=t[n];w(t,n);if(!t.watchers){a(t,"watchers",{})}if(!t.watchers[n]){t.watchers[n]=[]}for(var o=0;o<t.watchers[n].length;o++){if(t.watchers[n][o]===r){return}}t.watchers[n].push(r);var f=function(){return s};var c=function(o){var u=s;s=o;if(i!==0&&t[n]){l(t[n],r,i===undefined?i:i-1)}w(t,n);if(!e.noMore){if(u!==o){g(t,n,"set",o,u);e.noMore=false}}};u(t,n,f,c)};var g=function(e,t,n,r,i){if(t){for(var s=0;s<e.watchers[t].length;s++){e.watchers[t][s].call(e,t,n,r,i)}}else{for(var t in e){if(e.hasOwnProperty(t)){g(e,t,n,r,i)}}}};var y=["pop","push","reverse","shift","sort","slice","unshift"];var b=function(e,t,n,r){a(e[t],r,function(){var i=n.apply(e[t],arguments);h(e,e[t]);if(r!=="slice"){g(e,t,r,arguments)}return i})};var w=function(e,t){if(!e[t]||e[t]instanceof String||!i(e[t])){return}for(var n=y.length,r;n--;){r=y[n];b(e,t,e[t][r],r)}};var E=function(e,t,n){for(var r=0;r<e.watchers[t].length;r++){var i=e.watchers[t][r];if(i==n){e.watchers[t].splice(r,1)}}T(e,t,n)};var S=function(){for(var e=0;e<t.length;e++){var n=t[e];if(n.prop==="$$watchlengthsubjectroot"){var r=s(n.obj,n.actual);if(r.added.length||r.removed.length){if(r.added.length){c(n.obj,r.added,n.watcher,n.level-1,true)}n.watcher.call(n.obj,"root","differentattr",r,n.actual)}n.actual=o(n.obj)}else{var r=s(n.obj[n.prop],n.actual);if(r.added.length||r.removed.length){if(r.added.length){for(var i=0;i<n.obj.watchers[n.prop].length;i++){c(n.obj[n.prop],r.added,n.obj.watchers[n.prop][i],n.level-1,true)}}g(n.obj,n.prop,"differentattr",r,n.actual)}n.actual=o(n.obj[n.prop])}}};var x=function(e,n,r,i){var s;if(n==="$$watchlengthsubjectroot"){s=o(e)}else{s=o(e[n])}t.push({obj:e,prop:n,actual:s,watcher:r,level:i})};var T=function(e,n,r){for(var i=0;i<t.length;i++){var s=t[i];if(s.obj==e&&s.prop==n&&s.watcher==r){t.splice(i,1)}}};setInterval(S,50);e.watch=f;e.unwatch=p;e.callWatchers=g;return e})