I am using Camtasia which does the job by turning off hardware acceleration.
The biggest problems I have now are capturing at high enough frame rate (full screen, 25fps for PAL DVD production) and keeping audio in sync - neither of which behave particularly well in Camtasia. Full screen capture is the biggest problem - it produces a file that is in sync with audio but it looks more like a discrete series of photos (about 2 or 4 a second) than true video. If I capture in a smaller window quality isn't so great and audio loses sync but video is at least video.
I looked on VideoHelp and they point to a number of commercial apps that can do this sort of thing - but initial impressions are not great.
I found Tunebite at
www.tunebite.com which looks promising - unfortunately the demo version only works for the first 60 seconds of a clip so there doesn't seem to be any way to check and see if sync is maintained. Anyone used this and know what it is like?