Using VS 2005 (Team Edition for Software Architects) and VSTO 2005 (and
Office2003).

Creating an Excel Workbook project.
Adding code in ThisWorkbook.ThisWorkbook_Startup which adds a new
msoControlPopup to an existing menu.
The code also sets up a click event handler, "myMenuItem.Click += new
_CommandBarButtonEvents_ClickEventHandler(ClickHandler);"

The handler as:
private void ClickHandler(CommandBarButton Ctrl, ref bool CancelDefault)
{
   MessageBox.Show("My menu item was clicked");
}

This works fine when I start debugging and clicks the menu item (MessageBox
shows up), but when I repeat the click without restarting the debugging, the
messagebox does not show up.
Anyone knows why ?