Again, I'm writing a smart client application using VB.NET. I've been
writing web applications for the last few years and am new(ish) to
Windows Forms programming using .NET.

I have some MDI forms that move smoothly when being dragged and others
that don't refresh/aren't redrawn nearly as well when being dragged.
I've no idea what causes the difference in behaviour. Any idea what
might cause the latter?

Thanks

Daft.Geezer