Alright, thanks (I'm having isssues - apparently, the new disk was just enough to make the computer reset itself occasionally for no particular reason).
Yep, though it wouldn't make a difference - the system isn't booted from that HD, nor is it used at all when the restart happens. In any case, my theory has changed - the new one is that the new memory is causing the problem (I had 2x512 and wanted another gig; however, I mistakenly figured the board had 4 slots, while it has 3, so they put in a 1x1GB module in the last slot... and now I hear that might be what's causing the restarts).
Yep, though it wouldn't make a difference - the system isn't booted from that HD, nor is it used at all when the restart happens. In any case, my theory has changed - the new one is that the new memory is causing the problem (I had 2x512 and wanted another gig; however, I mistakenly figured the board had 4 slots, while it has 3, so they put in a 1x1GB module in the last slot... and now I hear that might be what's causing the restarts).