hi ,
i am facing the similar kind of issue with slight difference , the Error is like ,
URI: http://www.ok-soft-gmbh.com/jqGrid/jquery.jqGrid-4.4.1/js/jquery.jqGrid.src.js
Code: 0
Char: 5
Line: 1662
Message: '$.jgrid.formatter.integer' is null or not an object
have i missed any file and i have added grid.locale-en.js and all the required js still unable to predict this 
thanks