I've got a fresh 10.6.7 build with 5.5.2 installed and I've found that if the machine has been asleep for a period of time I cannot launch AMC.  The launch stalls on loading audio plugins and eventially errors out with a message stating there's been an AMPI subsytem error (I'll post the exact message later if needed) and what I've found is that a restart of the system fixes the problem. 

I have turned off the power warning message - the same energy saving settings never caused a problem with 10.6.3 and AMC4.

Is this a possible bug?  It happens consistently and the other fixes suggested for AMPI errors don't work/apply here.

Edit: Added error message and also found the problem occurs even after less than 10secs of sleep - there's something it doesn't like about the Mac going to sleep.

Not sure why you're having the issue now vs. previous versions, but from personal experience I have never allowed Avid Macs to go to sleep.  One of the basic setup functions is to uncheck "Put computer to sleep" or "Put hard drives to sleep."  In the past sleeping could cause issues during long renders, digital cuts, etc.

Unless anyone knows of a reason NOT to do it, I would strongly recommend changing those energy settings now.

If it was my personal machine then that's what I'd do (btw, sending idle drives to sleep is already turned off).

Unfortunately it's a Mac that's used by students, and we've got 20 Macs, and getting/teaching them to do the right thing after they've used them is somewhat futile.  You should see some of the scripts we've created already to automate and bypass exports and other things!

Anyways, there's a big energy saving drive going on here and I'm just trying to do my bit

I'm not seeing that behavior on my systems.  I do know that having the CPU go to sleep while Media Composer is running is almost always disastrous, having the Mac go to sleep between launches doesn't cause problems.

Do the affected machines have SoundFlower installed?

No SoundFlower and Avid isn't running...

Kevin Klimek:

 One of the basic setup functions is to uncheck "Put computer to sleep" or "Put hard drives to sleep." 

Is there a checklist available for mac basic setup ? I have a printout of an old PC setup checklist and it was very useful. Now I am setting up a new mac system I would like to find this document if it exists?

Cheers !