Anyways, so I updated the drive in the 6100 and after a few tries it ran, ironically enough. I then proceeded to reupdate the cheetah in the 8100 and the machine still froze upon loading the extension. However, it soon did load pass the extension but it was very problematic. Retrospect wouldn't backup the machine, and I couldn't turn the machine off or put the cover on without the machine messing up again. Consequently, I have the 8100 back in its original configuration and awaiting to talk to tech support again so we can get an RMA number and hopefully get one that works reliably.
Virtual memory is turned off.
Frankly, I am willing to put up with it for the performance gain I get from the drive. The user had changed the font of her clock to some non-standard type and like someone suggested, I changed it to a common Apple font and the problem immediately disappeared. Absolutely no crashes or incompatibilities at all. This thing is wonderful. Macbench 4.0 returned scores of 593 for the cpu and 665 for fpu performance.