I suspect you have a similar problem to what I do(see: http://www.trirand.com/blog/?page_id=393/discussion/is-export-bugged-or-am-i-just-doing-something-wrong/&value=export&type=1&include=1&search=1&ret=all). Well first of all, I'm not sure import works like you are trying to do. I tried to something similar. On page entry I wanted to check to see if the user had a saved configuration so I did an ajax call which returns the json of the grid config if there was one. I then tried to load data like you're doing but it didn't work for me at all.

To see if it's even running correctly for you what you can do is this

grid.jqGrid('GridUnload').jqGrid('jqGridImport',{imptype:”jsonstring”, impstring:savedata,importComplete: function() {alert('something');}});

That importComplete runs when the grid loads. In my case it would never run without having the mtype and impurl in it. So, i just made a second call to my controller. After I fixed that I noticed some issues with export. I'm not sure why but when I export my grid it gives way more stuff in the json than I supply and that causes the import to break. If I manually roll my own json file I was able to make it work. By that I mean do something like this

'{“grid”:{' +