I'm trying out Vegas 8 and 9 on Windows 7 and when I preview my HDV timeline to my OCHI device (Canopus ADVC-100 connected to my Sony Monitor) the previews on my Sony monitor flash black periodically during playback. I did not have this problem using Vegas on XP. Any ideas?

System Specs.
Intel Quad 2.6ghz
4 gigs ram
Gigabyte EP45C-DS3R
Nvidea 8800 GTS

Thanks, Marc