12.3 video speed problem

I installed 12.3 today and to my horror, 23.976 video plays back way too fast, maybe at 29.97. The audio seems to be fine, but the video rapidly gets ahead and out of sync (picture drifts early). I trashed the prefs and did the usual voodoo, but the problem persists.

I have a mix session tomorrow, so I might need to downgrade back to 12.2. Is that possible? Is this a bug in 12.3? Or is there something I can do to fix it?

Thanks,

Ellis

12.3 video speed problem