Garbled Screen [GZDoom 1.0.18]

[Comreak]

When I run GZdoom, the screen is all garbled and flickers a bit. Screenshots below:

Title Screen(?):
http://home.earthlink.net/~comreak/imag ... -title.jpg

Menu Screen(?):
http://home.earthlink.net/~comreak/imag ... m-menu.jpg

The same thing happens in ZDoomGL.

My Specs:
Windows XP
Radeon 9800 Pro /w Cat 6.5
1 gig of ram
Athlon XP 2100+

Edit://
Yep, anything below"High Quality" under "Standard Settings" causes problems. Custom settings also seem to cause problems (turning off AA or AF brings the flickering back).

[Graf Zahl]

Not again. You have to set your graphics driver to higher quality settings, especially for mipmapping. Something in there doesn't work right otherwise.