I just discovered a nasty quirk that can mysteriously kill toolbar buttons. If you raise a MessageBox while processing the Load event while launching a form, the toolbar buttons on the form no longer receive the buttonclick event after it appears on screen. They depress and display tooltips, but don't produce any action. I am using Visual Basic .NET in Visual Studio 2003.

Toolbar buttons fail to recieve buttonclick event.
ZACK2K6
This actually makes sense, since a dialogue box is system modal and disables other controls.
You can emulate a dialogue box by implimenting a small form, and doing a .show on it. This won't disable the other controls.