I just started up a project that I hadn't worked with for about four weeks. Now about half of the scenes play back with a pronounced echo. If I isolate each of the four audio tracks independently, they of course play back fine. But if I play the clip (either in the viewer or the timeline) with all tracks enabled, it sounds bad.
This problem happens on BOTH of the MacPro towers I have. It's not isolated to one machine. I've trashed prefs, waveform caches, audio render files, without success.