Well, try this!!!
.PCI master read caching, default setting=Disabled
.PCI master time-out, Default setting=1
Setting above options to Disabled/3 will lead to the same result with VIA Latency patch V0.14 and may help SB Live 5.1 sound issue. .
VIA Latency patch V0.14:
http://www.viahardware.com/download...atency_v014.zip