You really have to watch out for cards that have too much power draw. This became an issue at first with many socket 7 AGP boards not being able to provide enough current for the TNT2. You could chance it and try an MX400. My ALi board worked with my GTS but not my TNT2U. It is possible that the die process shrink of the newer chips means a more powerfull chip can draw less power than an older chip.
What's the frequency, Kenneth?