Paul,

In addition to what Ko said, the form's Maximize and Minimize buttons have to be disabled. For debugging purposes you could try to invoke WhatsThisHelp with the following line:

ThisForm.WhatsThisMode()

On forms for which I need Maximize and Minimize, I use a command button that calls ThisForm.WhatsThisMode() which enables the What's this Help mode and displays the What's this Help mouse pointer.

Hope this helps.