Thanks sarode,

At least this confirms that my code isn't complete rubbish.
Is there anybody out there who could compile the code on his/her setup. I'd be interested in knowing if the buttons get redrawn fast on QT 4.1 or 4.2 on Windows. Is is probably better to set number to 250 to get a better idea of what is the problem. Basically it draws the buttons in two (or more phases), first some lines with text, next the complete button.
Heck, even a web app would be much faster than what I'm seeing now in this native app. If I can't resolve this problem I think I will have to check out wxWidgets again, which is sad as I was just starting to like QT.

regards,
p