Are you sure that you use the version 4.4.4? For example the demo uses jQuery 1.9.0, jQuery UI 1.10.0 and jqGrid 4.4.4 and I can't reproduce the error which you describe on the demo.

In any way if you have found an example when flitering of jqGrid works incorrect you should post full demo with description of the test case which can be used to reproduce the problem. Only in the case one will be able to reproduce, localize and fix the bug.

Do you try to use names of columns without dots: replace “a.id” to “a_id” or any other name for example. If you load the data from the server and use loadonce: true for the local filtering you can use jsonmap: “a.id”, but the value on the name property choose any other (without dots).

Best regards
Oleg