does this ever happen to you? on MC 4.0 - all clips in bin are fine - then come to one that appears black in the source monitor, but hear audio - edit to timeline, the whole clip is there! just wondering...
When you load the clip into your source monitor, go to your timeline and look at the source side tracks. Is the TV icon on the left of the V track toggled? If it's not, then turn it on and you'll get the picture back.
If it is on and the picture still doesn't show, I'm not sure what's going on.
That happened to me once at school while editing a video. I asked the lab technician what was up, he told me to switch computers. Don't know what that did, but it made me log out of the server (that had all the clips on it) and log in again at a new computer, so maybe that made a difference? Either way, problem didn't come back. Try and restart the program. Maybe it's simply that.