Once on standby mode, hold the power button (NOT THE EJECT DISK) until you hear it beep 2 times, it should restore your PS3 display settings. If that doesnt work, when your PS3 is on standby mode again ... hit the power button until you hear 3 beeps. It should take you to the new recovery page on the PS3 (thanks to v2.50 I believe) once you go there, restart it and it will work.

If that doesnt again, go to the PS3 General boards (us.playstation.com) users over there are pros on this stuff lol. Im there too:P