Ubuntu 10.10 Maverick Server makes system locks up at random intervals (i7 930; 12GB RAM)

I just reported a bug to Launchpad about the very same issue, five days ago. It is also an Intel Core i7-930, in an Intel DX58SO mainboard:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/665796

Most certainly yours is the same problem, your description matches too much with my problem. Check if your system timer interrupt freezes during these lockups. Keep this running in a terminal:

watch -d grep timer /proc/interrupts

You will need an external source of interrupts during the lockup in order to make the process scheduler operate and see the command executing. Pinging your computer from another machine (with a small interval) will help.

If the timer interrupt stops incrementing during the lockup, then it is the same problem. Please, add your system information to the above bug report so that we get attention from the Ubuntu developers:

ubuntu-bug -u 665796 -p linux