By adding a JSON.stringify(status) call to my status variable, this seems to make the setGridParam call happier and it behaves consistently.

The code is as follows:

function status_checkboxes() {
    status=[];

    $.each([$("#OnTrip"),$("#JUNK"),$("#SOLD")],function(i,e) {
        if ($(e).attr("checked")==true) {
            status.push($(e).attr("id"));
        }
    });
    console.log(status);
    if (status.length>0) {

      $(POL.currentGrid).jqGrid('setGridParam',{ postData:{ status: status }});

    }
    else {

      $(POL.currentGrid).jqGrid('setGridParam',{ postData:{ status:"off"}});

    }
    $(POL.currentGrid).trigger('reloadGrid');
    return true
}

$(document).ready(function(){

…

  $("#OnTrip").bind("click",status_checkboxes);
  $("#JUNK").bind("click",status_checkboxes);
  $("#SOLD").bind("click",status_checkboxes);

});

When I check JUNK, then SOLD, then un-check SOLD, it correctly sets the "status" variable to only ["JUNK"] but ["JUNK","SOLD"] is passed on setGridParam (confirmed with Firebug). Using Firefox 3.6.11 on a Mac.

All help appriciated. Thanks!

Greg