diff --git a/src/common/utils.js b/src/common/utils.js
index 7057c8b..f0e1b44 100644
--- a/src/common/utils.js
+++ b/src/common/utils.js
@@ -108,7 +108,7 @@
 
     retVal = {};
     for(i in obj){
-        if(!(i in retVal) || retVal[i] != obj[i]) {
+        if((!(i in retVal) || retVal[i] != obj[i]) && typeof obj[i] != 'undefined') {
             retVal[i] = utils.clone(obj[i]);
         }
     }