Glad to hear that you resolved your voodoo issues with your rig. Wish I had the expansion chassis like you as it would give me more options. Did you ever think about replacing your 9600 with a last generation G4 to retain PT5 and also run PT6.4, or give though to moving to a G5 with PCI or PCIx to run versions of PT6.4 to (PT9.x I believe as last version that can be run on a G5 with last version of OSX)? Would be interested to hear if you reviewed all of your options when you resurrected your 9600 rig, and what alternate plans you had in the event the your 9600 voodoo did not go away.
I have got to say it is unbelievably complicated to pull together and look at upgrades to Protools on older Mac's---I wish I could find a Pro tools matrix (excel sheet) that listed from the beginning of time, all Pro tools Software Versions, the range/versions of hardware DPS/samplecell/other cards (including buss interfaces supported (PCI/PCIx/PCIe), the range of digidesign/avid/other Audio interfaces both required and legacy that work with the PT SW version, and the compatible operating systems ranges of Mac OS, OSX and Win that it will operate on for multi-boot options--its an absolute pain to try to lookup all these interdependent requirements to get a good idea of what you can run on what environment to fully understand your options. At least with your expansion chassis you have more options open to you.
Ideally, I would be able to Run PT5.1 through PT9.x but I don't think this is possible, but PT6.x through PT9.x might be. I was looking to pick up an Avid Eleven Rack which needs PT9.x or higher to integrate into my rig, while still being able to boot into lower PT versions to run my TDM cards and 888 & 882 interfaces for the main studio mixing process. A G4 will allow me to run PT5 and PT6, and has a 3rd party add in card to support serial interface for my older Studio 5 and Studio 3 MIDI interfaces, but I don't think it will support PT9, and going with a G5 kills PT5 and reuse of the TDM cards and audio IO interfaces unless using an older G5 with PCI slots, but this also kills reuse of my MIDI Studio 5 & 3 patch bays. Just trying to figure out what the best route to take is, and don't want to spend a fortune to get up and running again--as I will be only using the rig as a personal system for the joy of making music and studio mixing my own stuff.
PS it was nice to find someone with close to my same old rig to bonce idea's against since i'm sure we have had some similar thoughts on this topic. Thanks for chiming in.