At least once a day I lose work on my (2 different) Intel i5 machines running Ubuntu 12.04. The entire system will freeze/lock-up/hang, and never return. At this point nothing works; even the caps lock key doesn't toggle the light on the keyboard; Ctrl-Alt-F1 won't do anything either.

askubuntu.com is apparently where I'm directed for support.

I suspect this is a kernel bug. But I simply can't keep losing work like this, so I'm anxious to try whatever it takes to get the thing reliably working.

Can you suggest

1. something I can try to fix the problem
2. an existing bug I can follow progress on and contribute to (from users/tester's POV)
3. the most constructive way I can contribute to helping fix the problem, keeping in mind that I do need the computer (so can't do things that might "brick" it!)