Alex,
Thanks. I posted the zip containing suite and log. I ran the same script in "iexplore" instead of  "firefox", this time i am not getting jscript runtime error. Here is what script does
- select item from combo box
- click submit button
- continue to next item in combo box
The loop does not continue after click submit button but if i comment it out i can see the loop continues with next item in the combo box.
 if (submissionType != null && submissionType.wItemCount > 0) {
    submissionTypeString = submissionType.wItemList;
    submissionTypeSeparator = submissionType.wListSeparator;
    aqString.ListSeparator = submissionTypeSeparator;
    
    for (var i = 0; i<submissionType.wItemCount; i++) {
       submissionType.ClickItem(i);
                 
       if (!submitButton.Exists) {
          submitButton = page.Find("value", "Filter Results", 100);
       }
       //all the items in the combo box are selected when this line is comment.. 
       //if not ends with first selection and successful submit.
       submitButton.Click();      
       page.Wait(); 
    }
}        
   
Thanks