I have had exactly the same problem (Karmic x86_64):
Update to 2.6.31-14-generic gave that same /dev/mem error message. I booted off the old kernel and dpkg-reconfigured linux-image-2.6.31-14-generic and that got it working again!? I have no idea why it failed in the first place..
I am getting the EDAC warning on this kernel, and on 2.6.31-9-rt also.
I have had exactly the same problem (Karmic x86_64):
Update to 2.6.31-14-generic gave that same /dev/mem error message. I booted off the old kernel and dpkg-reconfigured linux-image- 2.6.31- 14-generic and that got it working again!? I have no idea why it failed in the first place..
I am getting the EDAC warning on this kernel, and on 2.6.31-9-rt also.