Hello,
I'm using the 3.6.4 version of the jqGrid and also need to do exports of grid config, store it, and then reimport it at some later point.
The bug was fixed for the export, but when importing, the filter does not come right, the url takes the filter as [Object+object].
I had to quote the whole filters json string in single quotes at lines 163 to 166
if(gprm.postData.filters != undefined) {