Ok, I spoke to soon. I thought video was my only problem.
On Tuesday I planned to work at home, to get a lot of code written for OPUS and found my computer locked. I kept restarting it, kept getting kernel panics. The temperature was fine, there was no abnormal load, I tried a new kernel or four, and apparently got a bit more stability. The graphics problems were worse than ever, and I get fed up and bought an ATI HD2600 Pro, which solved all those problems.
Still the machine kept locking. I eventually began to suspect the memory.I’d already run memtest over the whole thing (one pass) with no problems, but then I tried booting into memtest after one lock, and got thousands of errors. Long story short, I’ve tried swapping modules, running on one module, nothing I can do will make the system stable. I of course had already tried a BIOS update. That was a problem in its own right – the most recent BIOS was incorrectly stamped and would not flash, I’ve notified ASUS who have taken it off the site.
Anyway, I’ve now found out I’m not alone. I bought slightly slower memory than I intended because I was warned of problems, but I’m now actually forcing it to run slower still. Having said that, others have reported this is not a successful stop gap fix since they are still getting crashes. So, for now, don’t buy this board until they have the memory issues sorted out.
I eventually began to wonder if the PSU was to blame, and though when I went to buy a new PSU I was advised of frequent problems with this board, I decided to get both a new motherboard (for gondolin) in time, and a PSU. The new motherboard still crashed once, though it was much more reliable, when I booted it back into memtest I get lots of memory failures in different locations. I’ve since installed the new PSU, and everything seems stable. Hurrah!