function submitbutton_click() {
    var submitbutton = document.getElementById('<%=SubmitButton.ClientID %>');
    var uploadobj = document.getElementById('<%=Uploader1.ClientID %>');
    if (!window.filesuploaded) {
        if (uploadobj.getqueuecount() > 0) {
            uploadobj.startupload();
        }
        else {
            var uploadedcount = parseInt(submitbutton.getAttribute("itemcount")) || 0;
            if (uploadedcount > 0) {
                return true;
            }
            alert("Please select the GPCM database to upload.");
        }
        return false;
    }
    window.filesuploaded = false;
    return true;
}

 

I put breakpoints on each of the red lines above -- one on the call to uploadobj.startupload(), and the next one on the end of the condition. Thus I can see when the call starts, and when it completes. However, even though the file is uploaded, the second breakpoint is never reached. I also breakpointed the third red line above, in case somehow it got there, but it never does.

 

FireBug also did not register any javascript error, which makes little sense. And IE did not report any page error, which it usually does if javascript fails.

 

This appears to be entirely between this call of "startupload" and your HTML module on the web server.