[Qt-creator] MainWindow::paintEvent() constantly called

[Mike]

Greetings all,
I'm using QtCreator 1.0.0 on Linux Ubuntu 9.04 Jaunty.
I have a very simple first project that has a main window containing 
only one Lable which I use to display a picture from my web-cam. This 
works fine, except, the paintEvent() is constantly called. It seems that 
updating the Lable causes a trigger to re-call the paintEvent() 
function. If I ignore the re-call each time after I update the Lable, 
then everything works fine. Is this a known feature/problem?
BTW thanks for a great IDE, it was just what I was looking for.
Cheers, Mike