Re: Trying to make headway into finding the Xid crashes source...
Try running without apic. (noapic in kernel command line)
It seems to have worked for me (I'm not certain yet)
DEV: Intel S5520SC, 2xX5680, 36GB, 5x320GB, GTX470, F19/x86_64, Dell U2711.
SRV: Tyan Tempest i5400XT, 2xE5335, 8GB, 4x2TB, 9800GTX, F19/x86-64, Dell U2412.
VCR: Gigabyte GA-M61PME-S2P, A64/5000X2, 2GB, 1x320GB, 8600GT, F19/x86-64.
LAP: ASUS N56VJ, i7-3630QM, 16GB, 1TB, 635M, F19/x86_64.