Craftech,

I had some of those black frames "between" clips with V. 3.0c when scrolling around on the timeline (see my post in that thread), but they never showed up in renders.

I've been using the Vegas 4 beta and now the release for about as long as they've been out, and I don't think I've experienced any of that. In fact, I haven't run into any problems.

But all watch for anything weird like that and report back here.

G