I modified the basicdrawing example to create my own program that is very similar. It merely draws text in the RenderArea widget instead of polygons, etc.

When my application starts up, paintEvent() runs and everything looks good. When I change something (like the text string), I do update(), but nothing is repainted. Same thing with repaint(). Just to make sure, I did setUpdatesEnabled(true) immediately before update(). It still does not work.

If instead I resize by moving the corner of the window with the mouse, paintEvent() runs, and everything looks just as I expected, with the updated text string painted. Currently, resizing the window is the only way I can repaint.

I am using Fedora 11 Linux with Qt 4.6.2. I see people recommending Qt 4.6.3, but I hesitate because I compiled basicdrawing with 4.6.2, and it does update() just fine.