FC5 - audio not working, what to try?

[B Wooster]

On FC3, audio was working fine on my system.

On upgrading to FC5, audio is not working.

xine/mplayer provide no sound.
Using the system-config-soundcard utility, I can see it says it found:
Vendor: Silicon
Model: Integrated Systems [SiS] Sound Controller
Module: snd-intel8x.0
But when I click on the play button on that window, I get no sound.
It says look at /root/scsound.log, but not sure what to look it -
nothing jumps out.

Any ideas on what I should try next?

Surprisingly - I also have Leadtex WinFast TV Capture card in my
system, and using "tvtime", I can watch TV - and the audio on that
works!