With some help from Jens, we've confirmed that svga is the correct driver for this chipset, and after the holidays, someone is coming back who can provide a working XF86Setup file.
But that's in a couple of weeks :) The problem is that launching X as XF86Setup configures it for this chip hangs the video quite hard--the video doesn't come back at all after killing the X processess. Does anyone have this configuration running, or a wild gues on how to fix? rick --
