Overclocking failed!?

damn guys i need your help i got some fucking problems!!!!!!!!
today i started my pc everything was ok no problems...
later i restarted it and it doesnt boot!!!!!!! it stopped in the damn BIOS!
i restarted again (manually by reconnecting the power i disconnected before) and again nothing happened
my last idea was to go in bios setup by pressing the "del"-key and i finally got in the bios after the message "OVOERCLOCKING FAILED"
i checked everything but it was how i set it before.
then the pc booted and i looked if the clocks are ok BUT there were standard clocks now, not as in bios!
could you pls help me with it or should i have to use stock clocks now??

CPU: Intel core2duo e6420 @ 2.5 ghz with stockcooler (stockclock is 2.133)
RAM: G.E.I.L. 2x2 gb kit @ 780 mhz with 4-4-5-13 (stock is 800 mhz with 5-5-5-15)
mainboard: nvidia 680i by asus

--> the overclock was no problem before and i changed no hardware!

FIXED IT!!!!!!!!
only reconnected the power connecters in some different ways and clean them from dust^^

LOL yay!!!

I found on asus boards that it just happens. Not necessarily something bad with overclocking, it just happens. Usually after pressing the reset button.

I never pressed the reset button