I realize that the problem we are trying to solve here is because of our authentication mechanism (we are using JAAS), but I'm wondering if anyone has any argument against adding the XMLHttpRequest object to the loadComplete() function call?

Looking at the source code, it's a VERY easy change as the populate function simply defers to jQuery's $.ajax(…) function and the code that calls the jqGrid loadComplete function can simply take the first parameter passed (the request object) to the $.ajax(…).complete(…) function.

The problem is that when JAAS detects that a request is made to a protected resource and the user's session has expired, it redirects the request to the login page.