Quake 3 Issues

I had a 64MB Geforce 2 MX which had good image quality but was slow. I didn’t see any graphical glitches while using it. Recently I changed it for a Gigabyte GF1280 Geforce 2 MX 32MB which was more than twice as fast. All games are working great except Quake 3. It has lots of graphical breakup around shadowy areas and totally kill the games appeal. If I turn GL Extensions off, it works properly but obviously slower. The only other OpenGL game I have to test with is MDK2 which works perfectly. Any ideas to what is causing this and how it can be solved? I will appreciate it immensely if you could mail me at vjd@hotmail.com with any responses. Thanks.