[gears-users] Problem with Desktop.openFiles

[dviner]

I have a page that uses Desktop.openFiles(), but a user is reporting a
problem.  The user is using Firefox 3.0.5, Gears
0.5.4.2;official;opt;win32;firefox.  The error message received in the
Firefox error console reports this error message:

Error: browser.addProgressListener is not a function
Source File: 
file:///C:/Program%20Files/Mozilla%20Firefox/components/GoogleDesktopMozillaStub.js
Line: 434

This clearly seems to be an issue inside Gears.  I have used this same
code myself successfully with other users and platforms.  But, this
user can make this error happen every time.  So, there may be some
edge case that's not being captured properly inside Gears.

The code that invokes the openFiles method is:

function browse() {
    var desktop, msg;

    desktop = google.gears.factory.create('beta.desktop');
    msg = "AboutMyBaby Photo Uploader requires Gears.  It's a free
program that works on all operating systems and browsers.";

    if (google.gears.factory.getPermission(
            "AboutMyBaby Photo Upload",
            "", /* TODO: Find an appropriate png */
            "The AboutMyBaby photo upload feature requires Gears."))
    {
        desktop.openFiles(
            AMB.files_selected,
            { filter: ['.jpg', '.gif', '.png'] }
        );
    }
    return false;
}

How can I solve this problem for the user?

Thanks
Dave Viner