Extjs 4.2.1 hidden field - how could inputEl.dom be undefined?

As part of my application I've created a form with a Ext.form.field.Hidden element. For some reason the 'dom' member of my inputEl is undefined. It's causing an Uncaught TypeError at line 86938 of ext-all-debug.js when I try to set the field's value programatically:

Code:

setRawValue:function(value){
 var me =this;  
 value =Ext.value(me.transformRawValue(value),''); 
 me.rawValue = value;
 if(me.inputEl){  
   me.inputEl.dom.value = value;// <--- dom here is undefined
 }
 return value;
},

Please understand I'm unable to post a minimal example; this is part of a large application and I cannot reproduce the error starting from scratch.

Can anyone suggest how this might come about, or what I can do to further investigate?



Extjs 4.2.1 hidden field - how could inputEl.dom be undefined?