Well, shortly after I finished my prior post, I realized I still had a problem. Though the Hotfix in KB 943195 fixed my green video problem (captured HDV video (.ms-pvr format) would appear green during playback in Movie Maker, in Media Center and in Windows Media Player), I discovered I still had a problem during capture. I wouldn't get anything appearing in the capture preview, yet the video was coming in fine and I was able to edit the video after the capture was done. I decided I would live with the issue for awhile and see if Vista Service Pack 1 would fix anything.
So late last week, the update to SP1 happened on my computer. The first thing I checked was playback of HD video. It worked fine. Then I tried capturing and *it worked!*. I was so excited, at least until I tried to edit the video. It now appears as all black (sound but no video) when I try to edit. This is true straight from the collection or from the project timeline. It's even true when I open up a project that just last week was working fine.
Hmm... anyone have an idea? Could it be related to the ATI HD2400XT video card or the drivers? It seems likely since swapping video cards to an nVidia got everything working as expected. However, I have the latest Catalyst drivers for the card.
Oh well, the saga continues.