I'm having a really annoying problem with 12.04 that I can't seem to solve. If I leave the computer unattended for more than 10 minutes it goes into power saving mode and switches off the screen. The only way I can get back on is to log back in, which is VERY tedious. I have gone into the system setting for power and set it to 'Don't suspend', yet it keeps on doing it, so what am I doing wrong?

Any tips would be appreciated, as I'm currently trying to use my Ubuntu-based PC to display some information I;m using for a writing project, and I either have to keep remembering to move the mouse every few minutes, or go through the log in process again to get the screen back up.