After a short amount of time running the viewer graphic artifacts appear, specifically pixels being redrawn from the center outwards, these artifacts vanish for a few moments after changing the graphic settings but then return. I have tried running the graphic settings at everything from low to high, and various custom settings. UPDATE: further experimentation, I believe this directly related to to having VBO activated in hardware settings, after disabling no further artifacts appeared. to recreate: run the new release client with an ATI 9550 card after approximately 10-20 minutes of use graphic errors will appear.