them in CS6 some AIF files stop showing any wave form and playing (the Mp3's are fine).
This doesn't happen on all timelines or all the time - but one timeline in particular. The audio is gone both when playing a single clip in the source monitor - and when playing a sequence in the program monitor. But when I go back to the original file - it plays fine (these files are stored in an external hard-drive enclosure attached to the computer). But even when I re-import the audio file - it doesn't play in the timline.
I looked at the audio channel as you recommended - and both left and right are selected. So I didn't need to switch from "none"..
How great if that would have fixed it!! Any other ideas?