Font characters disappear at random
I've been having a problem on my linux box for a while now. Often random characters will be invisible. Moving the screen up or down or highlighting and unhighlighting the text will change which characters are missing. There is still space where the characters belong but they are missing.
This occurs in many different programs ranging from firefox to mythtv. The odd thing is there have not been any other graphics glitches that I have noticed. Though this machine is basically only used as a myth box.
Anyone have any idea what might cause this?