video player blank window with SiS chipset

[Andy]

Hi

I have a problem with Totem.

I have installed "warty" on a PC with a PCChips M841 motherboard. It has
  an SiS 740 northbridge with integrated graphics (SiS 650/651/740
compatible). Ubuntu has installed the correct (sis) driver and X runs
with no problems.

However, there's no video output from Totem - whether from a video file
(only sound plays) or an audio file (no "gorm" visualization). All I get
is a black window.

I know that it _can_ work on this PC - I've had Mandrake on it and
successfully run Totem and other media players. My XF86Config-4 file
looks correct to me (unless I've missed something) - I can post it if it
helps.

Anyone else seen this? Know a work-around/fix? Or should I report this
as a bug?

Cheers

Andy