I think it is a problem with the latest matrox driver, apparently a lot of matrox staff are leaving to join ATI. Anyone running IB option trader on a matrox successfully?
Before buying a new card, it would be worth confirming that you have the latest Java version. There is also an option for the JRE command line that fixes some of these sorts of problems on Windows (-nodraw=true or something like that). I hardly ever use Windows so I've forgotten the exact string but you can Google for it. As a bit of a long shot you could also try the IBM JVM. Last time I tried it (on Linux) TWS worked OK with it.
OptionTrader in IB TWs continues to be problematic even with a new graphics card. I have to logoff and reboot to get working again. Hopefully 846 will be better.