Hi there,
We are having some problems to with autocad Architecture crashes a few times a day. We recentley got a couple of new workstations, i7-930 2.8Ghz, 6GB 1600Mhz Tri Channel and nVidia GTX 460 (not top end I know but a lot better than what we had before!!) but CAD keeps crashing. Oddly the other PC runs Autocad LT 2011 and has only crashed a couple of time.
My only guess is that Autodesk are yet to certify any of the Fermi based nVidia graphics cards and maybe then this will sort out our problem.
Any other thoughts would be welcom though.
I had the same problem and ended up getting a new high end computer and it seemed to solved the problem until the file increased in size. Found out I was lazy and ignored the "warnings" that one can review under Manage/Inquiry-warnings. Once I cleaned up the data file, I've had no more problems. Reinstalled the clean file on the old computer and it also stopped crashing.
Don't know if this is your problem, but it sure was mine.