Weird font problem

I'm sure this is probibly a Qt problem, or maybe an NVidia driver issue...

The comment text is not visible: http://nighthawk.co.za/webissues.png

As you can see from the screen shot sometimes it is fine, (this was after moving the cursor over the text)

If anyone else has had this issue and fixed it, please let me know how?

Tested on:
Debian Etch 4.0r1
Qt 4.2.1-2+etch1