Mootoo wrote:
After idling for a while (just did it after an hour today, at least) Ubuntu just freezes - cursor is still functional, but everywhere else is black and I'm unable to operate it any other way except restart it. Anyone know why? I thought it might be a graphics issue, but it still happens after the computer has been substituted.
I'm not quite sure what you mean by 'after the computer has been substituted' but it seems the machine is going into a hibernate/suspend and not resuming properly.
Try disabling automatic hibernate/suspend and see if that fixes the problem.