[Wine] Trouble with directx games on wine-1.2 64 bit

[doctordruidphd]

Ever since the RCs and the release of 1.2, I have been having trouble with directx based games not working properly. They did work under wine-1.1.3x. The problems are: video very slow and jerky, about 1 fps, objects appearing as "tears" on the screen, missing some textures, and screen going blank during certain effects.

System: 64-bit kubuntu-10.04, dual NVIDIA 9800GT w/ 512 mb, plenty of disk space (hundred gb free), 8mb ram.

In the older versions of wine, I was able to tweak video settings in the registry, and get the games working. Using winetricks to do those same tweaks, I cannot fix the problems. 

Specifically,
"The Witcher" - slow video, rendering problems as described above.
"Wolfenstein" - Very slow video.
"Return to Castle Wolfenstein" - won't start or run at all, won't reinstall.
"Singularity" - Very slow video (~1 fps).

These games are all installed in their own .wine-gamename directories. Winetricks is started with "env WINEPREFIX=/home/myusername/.wine-gamename", and winetricks reports making changes in the proper .wine-gamename directory, so that seems to be working.

Because this is going on with all the dx games I use, I suspect a configuration or other more general problem, rather than a problem specific to one game, hence my posting it here.

Note that 3D linux games (Nexuiz, Sauerbraten, others) work fine. I have tried both gnome and kde desktops, both with and without video effects enabled.