if i turn on the GroupBy grid feature as follows :

            {
                     name: "GroupBy",                     
                     type: "local",                    
                     groupByAreaVisibility: "hidden",
                 },

, the moment I grab a column header in IE I get the following javascript error :

Line: 6
Error: Unable to get value of the property 'msie': object is null or undefined

It's occurring in jquery-ui-1.9.0.custom.min.js

Perhaps I'm using a too-recent version of jquery UI ?

FYI - same error happens when I add the igGrid feature for "resizing"

thanks.

Bob