Here is a question for you.

I previously used part of the tree code to download server side file (similar to the right-click/Open/Download option), but as some of the export information is large I added a progress bar. This worked fine in version 2.2 and I am just upgrading.

  var progressMessage = Ext.MessageBox.wait("Export to "+ item.exportFormat + " in progress",
                "Grid Export")
  var callback = function() {

            Ext.EventManager.removeListener(frame, 'load', callback, this);
            setTimeout(function () {
                }, 200);
            setTimeout(function () {
                }, 220);

        Ext.EventManager.on(frame, 'load', callback, this);

The problem I have is that the callback does not seem to be called.
Even if I put an alert in, the code never seems to pass into the callback. I cannot see it either in the debugger (firefox or chrome).
Obviously the concern is that also it is not clearing the iframe.

Does anyone have any ideas what has changed to break this?
Thanks in advance