I'm aware of the recent SxS driver update (v1.045050) to fix issues with macbook pro's and snow leopard have installed that version on my OSX 10.6.2 system.

Everything was working fine for months, until just recently when my macbook pro (2008 unibody) decided to hard crash at shutdown every time.

Once I uninstall the SxS drivers it shuts down normally. I've tested this repeatedly, trying to re-install the drivers. Each time I install the drivers, crash at shut down. Each time I remove the drivers, smooth shutdown.

So I wracked my brain trying to think about what changed from when my system was stable, until now. I can only come up with the recent ProKit upgrade 5.1, as well as the most recent security updates I've installed.

Is anyone having this issue, or have any advice?

Ok after a day of tweaking I figured it out. I'm putting the solution here in case anyone else has this issue.

It seems that the problem was with Avid Media Composer Digidesign drivers.

Once I deleted the digidesign folder from /Library/Application Support, I was able to use shutdown normally without going into a kernal panic, and still have the SxS driver installed.

The SxS and Digidesign drivers somehow conflict, and cause this issue at shutdown.

At least this worked for me, I hope it helps. Unfortunately I seem to have to choose between Avid and SxS drivers at this point.

John, thank you for this (to me, also a MacBook Pro/Snow Leopard/Avid person) very important post. Two things:
1. do I need the digidesign folder in my Application Support? Will Avid work fine without it?
2. Avid just released a new plugin (update): 4.0.5.2 I'm hoping this might solve the software conflict problem, but if it doesn't, I'd love to know the answer to 1. above.
Cheers,
Malcolm

should have included this:

Avid Editor Patches (http://www.avid.com/support/downloadcenter/editorPatches.asp)

(sorry, don't know how to make it a live link)
Malcolm