Hi guys, this might be completely edge case(or even applied in the wrong place) in which case feel free to ignore, but I've had to make an adjustment to ColumnModel.js 's setConfig method to avoid an annoying error (doesn't show up in firebug) in one of my applications.
Specifically adding " && c.editor.el" to the second if block in the function. See below:

PHP Code:
    /**
     * Reconfigures this column model
     * @param {Array} config Array of Column configs
     */
    
setConfig : function(configinitial){
        if(!
initial){ // cleanup
            
delete this.totalWidth;
            for(var 
0len this.config.lengthleni++){
                var 
this.config[i];
                if(
c.editor && c.editor.el){
                    
c.editor.destroy();
                }
            }
        }
        
this.config config;
        
this.lookup = {};
        
// if no id, create one
        
for(var 0len config.lengthleni++){
            var 
config[i];
            if(
typeof c.renderer == "string"){
                
c.renderer Ext.util.Format[c.renderer];
            }
            if(
typeof c.id == "undefined"){
                
c.id i;
            }
            if(
c.editor && c.editor.isFormField){
                
c.editor = new Ext.grid.GridEditor(c.editor);
            }
            
this.lookup[c.id] = c;
        }
        if(!
initial){
            
this.fireEvent('configchange'this);
        }
    }, 
For some reason (most likely because I'm loading column model configs lazily and via JSON server responses with the MetaData change) the request to setConfig was failing (without reporting an error) and I traced it to the editor.destroy() method. I've got a feeling that the editor config whilst existing wasn't instantiated so trying to destroy the non-existant object was throwing an error (albeit an invisible one).

I may just be being an but thought I'd bring it to somebodies attention just in case
Thanks!