Help. Desktop randomly goes into "Power save mode"

[vbx]

Don't know what happened, but this is a 2 month old build and never had any problem til today.

While watching live TV, the monitor turns blank, and says, "No input data, will switch to power save mode".

When reboot it, it goes to "resuming windows", while it's doing that, it again says, "No input data, switching to power save mode"...

This is on Win7. The only thing I did was update to the currents ATI Catalyst Control Center, 3 days ago.

I now have it logged onto XP, with no problems? I will try to log back in Win7 later.

So wth went wrong?