No Audio On Playback

[stickleback]

I've have a situation where certain playlists won't play audio. Specifically, I have ten drum tracks grouped together and on certain playlists I see the waveform, but there is no reading in the channel meter and no audio. I select a different playlist and the audio and meter reading are fine. Any idea what's going on?

iMac i5
OSX 10.6.8
PT LE 8.4
003 Rack
Focusrite Octopre MKII

[stickleback]

As a work around, I just created a fresh session importing session data and was recording along fine and playback was good until I suddenly got a frying sound that just about blew off my headphones. And now I'm getting that "fried" sound on the playback of just the tracks that I just recorded. Maybe my 003 is fried? But why on only specific tracks?