Screen dimming off for no reason? - DELETE THREAD PLZ

Hey

I have an SR 2.2 MBP. I've unticked the "dim screen before sleep" option, yet my screen dims anyway, but instead of just becoming darker it actually shuts off the backlight entirely. I have the screen sleep set to 10 minutes, but after maybe 2-3 minutes sometimes the backlight just turns off by itself. I can tell it's just the backlight off, because I can still see stuff on the darkened screen.

I thought maybe this was because I had upgraded from Leopard, so I reinstalled Leopard last night (erase and install) and it STILL happens!

Does anybody have the same problem and is there a way to fix it?

Thanks

Actually I should've used the search, there's a million threads on this lol. Maybe a mod can lock this up and delete it?