I bought a Chaintech GP-2302V (Avance ALG2032A) that unfortunately has some problems.
After installing drivers, it looks like this:

Shrek mode in 256 colors, almost correct display with some text artifacts in 16-bit colors, striping in 24-bit colors

I swapped the RAM chips for new ones and nothing changed. From searching on Vogons, one person previously had problems with artifacting and ddraw, but disabling ddraw here didn't change anything. I also tried Windows 95 and 98SE with many driver versions, but both had the same behaviors.

Has anybody encountered something like this before?