I don't think there are that many people using that specific product here on the forums. So I'm not sure how much help you'll get. These are my thoughts, based on my experiences with VMWare products over the past few years:

1. There is always a performance penalty with a virtual machine. Most times, this won't be noticeable in light duty applications, but video is often not light duty. Video capture can be quite resource intensive. My experience with USB TV tuners in the past has been less than optimal. I'd have to capture in a smaller window, etc. You didn't mention what kind of Mac you're using for a host. The Honestech requirements call for a 2GHz P4, so you'd want a Mac that's faster than that. I don't have any experience with very recent USB video capture devices so I can't say for certain how much faster, nor if it will actually help with improving video capture.
2. The virtual machine still has a SVGA II video card, even when you select 3D acceleration. This video card might not be powerfull enough for the Honestech software. Honestech may not have tested with a SVGA II card, believing that "no one would use such a old video card with our software." This would explain why the software works in Bootcamp, but crashes in a virtual machine.

So I don't know if you're going to have much more success getting this to work in a VM. Hopefully someone else has some ideas. Otherwise, you may have to use it only in Bootcamp.

So... since you're trying to use an Hosestech device... I'm going to be Honest with you...

You have a new Mac. It came with a most awesome batch of Video Capture/Editing/DVD Burning apps in the form of iLife: iMovie, and iDVD.

Yeah, I know this is a Fusion Forum, and we might or might not get your Honsetech to ever suck footage into Windows through Fusion....

But, may I suggest you "Stop Suffering", and beg buy, borrow or steal a Canopus ADVC100 or 110? Or ANY of the less expensive "Mac Compatible" Composite Video-to-Firewire/DV converters?

Really... it will free you of Windows for the (should be) fun and creative task of digitizing Videos, and let you do it natively, in a much more enjoyable, creative environment. Your Mac, as a Mac, is going to let you do things with video that would take the Windows equivalent of a combination vasectomy/root canal.

Can you DO it solely in Windows? Yeah, probably. In a Virtual Machine? Much less likely. Either way, see the "combination procedure" I mentioned above.
SAME exact exercise strictly in OSX and the iLife suite? You're going to have FUN. Actually ENJOY using a Computer again.

Having "Been there, done That" on both sides of the aisle... my advice is "If you don't absolutely NEED to do it with Windows, DON'T"

(And FWIW, I DO use Fusion for all manner of crazy one-off apps and GUIs that will never see OSX, and I LOVE it for that, but give me the Mac Equivalent of ANY windows app, any day...)

-art