Hi Mark,
I have 8.1, but I uninstalled it because of that same issue, plus a multitude of different problems I had. When you are capturing hdv, there is no preview available. It will capture, but you have to monitor it off the deck or camera. I use 8.0 now with my 64 bit vista op. It has the preview I need and it’s faster at rendering, which is funny. Vegas support couldn’t offer any answers, besides telling me it’s a known issue. The only fix I found is to stop using the 64 bit version. I’m actually happy now with it’s performance. The hassles I experienced though, were frustrating. I think it best to not use any of their 64 bit versions, unless you know how to tweak your computer. Maybe someone on here can offer some knowledge and positive experiences with the 8.1 or 9 64 bit.
– Kris