This may be old information for Dazzle DVC II users, but I'll post it any ways, as I recently found this to fix my audio sync problem especially for VHS captures:

Open registry
Search for SAA7114
Expand SAA7114 and look under AudioClockGeneration
Here you will find a reg key named reg3a with the value 9 - open that and change the value to 1

This fixed my sync problem....many thanks to Spawn's site for this fix.