If you use wkTask Manager to switch between applications, start applications, or close them and you happen to have Windows Mobile 6.5 with Touch Flo interface, your regular Windows start menu may disappear in certain situations and the only way to get it back is to do a reset.
The solution is to add “\Windows\shell32.exe” to the list of exceptions. No title or class name are needed.
Illustrated instructions are here:
You can also disable regular OK/X close button: