ok, small update on steps I've taken in my work to resolve the system hang on updating the DMI (which, according to my mobo manual, is the last step before loading the OS):
1. rearrange RAM in various permutations
2. dismantle my RAID and clear the HDD's, then clear the CMOS
3. flash the BIOS to the most recent version from ASUS
4. remove all expansion boards except my video card
5. remove everything except my video card, HDD's, and one IDE DVD drive
6. remove my SATA HDD's and replace with an older IDE drive
None of this has worked. It still gives me the same hang every time. I am running out of ideas quick.
My current last-ditch effort: install the dinky little sound card that came with teh Crosshair mobo. If the DMI controls resource management and reports IRQ's and such to the OS. This card's slot is smaller than anything I've ever seen and so is the card, so it's definitely dedicated When I put it in and turned the comp on, it did boot, so that's a good sign. But atm I'm just chalking it up to coincidence. I'll test more in the morning.
Also, the PCI slot just below this non-standard slot doesn't seem to be working, perhaps also screwing the BIOS. I haven't checked to see if this has changed since the installation of the small sound card, but before this I put my sound card in that slot and it acted like nothing was there. Moved it down to another PCI slot, detected it fine. Odd. I hope my mobo isn't damaged.
Anyone with any suggestions, I'm happy to hear them. Pulling my hair out over this. The system works flawlessly when it does boot, it's just the hanging before boot and constantly having to restart until it POSTs correctly.