cockpitvisit,

You're going to like this. The map always displays correctly if the bottom-left offset is anything other than zero, yes even when the offset is 1. What's more, it doesn't matter how large the maximized window is. Whether or not I have the Taskbar auto-hide or Vista Sidebar enabled (both of which affect the maximized window size) the app always goes white maximized (with 0 offset) and always displays correctly when the offset is 1.

Of course, I'm a software engineer so nothing surprises me any more (although I don't do Win32 API work so I can't help you here).

Hope this helps!

Regards,

Caesar