I've tried all the software patches mentioned here for disabling macrovision when capturing VHS tapes to my ATI AIW Radeon in XP, but none worked.
I read a quick post here about trying a RF modulator: it worked very well.

I have a Radio Shack RF Modulator Cat No. 15-1283A, which was about US $20 I think. RCA output from VCR to the modulator, then coax from the modulator to the AIW coax input. Works with ATI's software and Virtual Dub.

I realize capturing from coax is not the best, but for the tapes I'm capturing from, it's fine. I imagine the Sigma device is better, but in case there are persons out there who don't have a Best Buy nearby or don't want to buy one on-line, a RF Modulator may already be handy with a video game system to try out.

Just the same, I hope there is a programmer out there somewhere working on a hack that can disable ATI's code. The last thing I need at my computer is more cables and an AC plug because ATI feels the need for Macrovision.