This is happening on my 12-core Xeon Mac Pro with 16gb of RAM (Lion 10.7.3), nVIDIA GeForce GTX 285 card, so it is probably not an insufficient-hardware issue... plus nothing has changed in the system that would explain this issue.
I was working on a file combine several short clips a couple of weeks ago, and all was well, despite the fact that I was using the raw FLV files. They imported, showed up and played back in Source just fine, and when I created my sequences they all worked beautifully in the Program monitor as well. I exported them, they looked great, all was unicorns and rainbows.
Until I came back from a trip today.
I repaired my permissions and restarted my machine (I always do that after a time away), and pulled up my file. Nothing at all in my system configuration has changed in the time I've been away and no one else has used it. But when I bring up any of the files or sequences in the source or program monitors, all I get is black, no matter what magnification or playback resolution I specify. I can play them, everything looks normal, the audio plays as if the file is running normally... but no video. If i stop playback and click on the video in the program monitor, I will see a still from that video. But as soon as I play, black.
The strange part is that this also applies to the play MOV files I brought in, and newer ones as well. I've brought files in that are in QT (Apple Animation Codec). H.264, MTS (AVCHD), etc., all files that have previously worked just fine, and all of them suffer from the same issue.
I will do some more system cleaning and restart everything again, but has anyone hadf a similar experience, have an explanation, a solution, anything? I will be in serious trouble if PPro can suddenly not work for me.