My system has been at 2.7 GHz for the last 3 years (yes I Know its getting on a bit) however for some reason it has dropped itself back down to stock (1.8 GHz) even though I've not entered the bios for about a year and refuses to boot at anything other than stock. When I went into the bios to redo the overclock it will get to the initial POST screen showing 2.7 GHz, switch off and come back on at 1.8GHz. Like I said nothing has changed yet its deciding to be very awkward.