The problem currently with Trident cards is that the company is cagey about releasing information to the XFree86 project, and therefore support for these cards is choppy at best. I never got X to run right on my Presario 1200 with a Cyberblade, and I never really get a good display out of regular old 8Mb TGUIs, I save them for servers that aren't even going to be running X. According to the
status page over at the XFree site, there was support added for 2d under 4.2.1 I don't know if any distro has released under 4.2.1 yet, but a binary install is pretty easy if you want to give it a shot.
Luck,
Finegan