Weird random noises...

[Cerulean]

This is something weird to explain.
I had been working on a project for some hours, saved it, and opened another session. Then, even before hitting the play button, I started hearing these noises. They randomly show up on all tracks, I can see their peaks in the mixer window. None of these tracks are record enabled. I tried different session files, I rebooted my pc, I disconnected my Mbox2, nothing seems to work. Is this a known problem? I couldn't find anything on the net.
The sound is hard to describe, a bit like a muffled hihat or something...
kind regards
g.

[Cerulean]

Argh this is awful... When bouncing a track, these noises are included on it :s I don't know what to do! I've got a deadline to catch

[albee1952]

We need more info. List all the hardware you are using. If you have an external mic pre patched into the lighpipe of SPDIF inputs, you MUST set SYNC to ADAT (or SPDIF if that's what you use) or you will get pops and clicks in your audio.