Driver issue??

My app wont run when i set more than 256 colors. I get an assertion…illegal instruction…with the driver (ATION4AA.dll).
-Pentium II, 450 MHz,
-128 Mb RAM,
-ATI Rage 128 AGP, 32Mb (Driver v. 4.3.3225, 4.0.0),
-Windows NT 4.0
Tried goin to the ATI site and downloaded new driver, but same problem still. Any suggestions?

Is it just your own program that fails is this a developer question.