>We are seeing this effect in Windows 2000 and Windows XP so far. Haven't tested it on previous versions yet. Only on desktops, no WTS yet of this version. We don't use the API at all for this form. In fact, I have stepped through the properties and methods and cannot see anything unusual yet...

What are the parameters you're passing to MESSAGEBOX()? What type is the form? MDI or SDI? Any ActiveX controls?

I can't seem to duplicate this in a simple example.