I have an update to this ongoing problem.

I have now done the following.
Formatted Drives and reloaded OS and Library
Replaced SCSI Cable
Replaced SCSI Controller
Flashed all firmware

And oddly enough it still crashes in about 8 hours.
Now here is what i have found.

If I run the system with a Targus USB hub it will crash in 8 hours. New hub or old hub it doesn't matter.

However if I run it without the hub it runs all night long. I am up to 20 hrs.
Has anyone had any USB hub problems?

But in the end the really cool part is that I have 3 other systems running with this same hub and there are no problems on those machines.