My firm loves using this product and we just ran into a blocker issue. It seems that when we use grouping we can't collapse. And this issue is becuase we refresh teh grid every 100ms since we use cometd/web sockets to update the grid while data comes in throughout the day. With furthur investigation I found that it does collapse BUT everything becomes uncollapsed after the grid is refreshed. So if we refresh every 100ms it seems like no collapse happens. What I did as a bad solution which doesnt work well is to save everything that is hidden, refresh, then hide the rows I stored. Here is my bad solution, maybe there is a better one:

    var refreshGrid = function() {
        storeHiddenRows();
        theGrid.trigger('reloadGrid');
        hideRows();
    };

    var storeHiddenRows = function() {
        theHiddenRows = [];
        $.each(theReceivedTimes, function(key, value) {
            if ($('#' + key).is(':hidden')) {
                theHiddenRows.push(key)
            }
        });
    };

    var hideRows = function() {
        $.each(theHiddenRows, function(anIndex, anId) {
            $('#' + anId).css({ display: 'none' });
        });
    }

Thanks again! Use this plugin everyday!