Can't get X working on AS 2.1

[Christian Call]

I just installed Red Hat Advanced Server 2.1 on a machine that has a SiS 661FX-series video chip set in it.  Unfortunately, I can't get X to work.
 
No matter what SiS driver I choose in the Xconfigurator, I always get a message saying that there was a problem with my X configuration.
I've also had no luck trying to use the "Generic VGA" driver.
 
Is there a way to get AS 2.1 to work with this video chip set?
 
Thanks for any help...
 
-- Chris