Yes, that card can easily run OpenGlL. EASILY I said. You must have something set wrong I'm guessing. Tell me; are you going to OpenGL so that you can try the S3TC textures? What happens when you play UT using Direct3D as your renderer? If not, try this. It is straight from my how to manual that nobody ever uses apparently:
How to use the OpenGL Renderer:
(Print these instructions if you can)
OpenGL is a rendering method your video card may be able to use to give you slightly better graphics in the game. Most semi modern cards can or do have this ability. It may be to your advantage to try the UT in this mode. If you want to give it a shot, just follow the directions below.
1. Go to your C:\UnrealTournament\System folder.
2. Rename the file called OpenGLDrv.dll to OpenGLDrvOriginal.dll
3. Go to this link and download this zip file to your computer:
http://cwdohnal.home.mindspring.com/utglr/utglr28.zip
4. Unzip the file and copy the OpenGLDrv.dll to your C:\UnrealTournament\System folder.
5. Start the game and from the UT Desktop select options.
6. Select Preferences.
7. On the Video tab, select the Video Driver "Change" button.
8. A “Change Video Driver” option window will open. Select “Yes”.
9. The “Unreal Tournament Video Configuration” window will open.
10. Click the radius for “Show all devices”.
11. Highlight “OpenGL Support”.
12. Select “Next”.
13. Select “Next” again.
14. Select “Run”.
Done!
OK. So there you have way to install and use OpenGL Boss. Let us know how it goes. Go get my manual and see:
Chapter Four
“Tweaks for Your UT Player Installation”
for more about using OpenGL and using the high res textures too if you dare.