man i had THE SAME issue...after goin' back and forth support -lol...wow interesting...i went to 'check for updates'...it took me to this link:
http://www.pinnaclesys.com/PublicSite/us/Products/Consumer+Products/Home+Video/Studio+Family/Video+Capture+for+Mac+Support/Download+Area/Drivers+-+Updates/Leopard+patch.htm?mode=documents&Display=1
and i downloaded 1.0.1 ...and it updated even though it stated that i needed Leopard...i call it the sure favor of God...LOL...now i can preview audio and video...hope this helped...