USB Video Grabber not recognized

I have tried three video grabbers and they aren't recognized in Parallels 3, 4 or Beta 5 versions, yet they all work just fine when I boot my MBP up with WinXP Pro. The video grabbers are a Pinnacle Dazzle, a Plextor, and ADS Express 192. The manufacturers have no solutions and refer me to Parallels support and theyrefer me to the manufacturers.

I'm not interested in getting a video grabber for the Mac OS since the programs I use are PC based.

Hopefully someone has run into this issue and has found a solution.

Thanks for looking,

Don