Tom,

I haven't been able to identify the issue but I know that following an upgrade path from 10.5.x to 10.6.x has caused issues with Catalyst. I have also personally seen this error before on 2006 Mac Pro machines with X1900 GPUs.

While I am aware that the issue is related to a bug in the quicktime frameworks of OS X, it is not something easy to pinpoint or explain.

The best suggestion for any future practice is to Clean Install 10.6.3 (most recent official DVD from Apple) and then update to 10.6.6, THEN configure and install apps/drivers, etc.

If your Catalyst systems are as simple as the Cat app on a mac then this is best. If however you have complex configurations, user preferences, and items you do not wish to take the time to install (IE greater than a few hours) then there is an additional step:

Use an auxiliary disk to boot to (the install DVD is fine but I have thumb drives with default system images). Once you boot to the aux system, use the Disk Utility to create an image of your 10.5.x system partition.

Once the image is created and stored as a DMG on another disk, perform your clean install to 10.6.3 and all updates to 10.6.6.

Then use the Migration Assistant to migrate from the DMG image to the newly fresh 10.6.6 install.

I want to note that this is only necessary if the scope of work to clean install everything on your system is significantly great. In all honesty, I've never had a Catalyst System that I couldn't clean install in less than 2 hours including software, drivers, etc.