There is a jumper its called CLRTC. In the manual go to 2.6 in it.
The jumper is located near the BIOS chip and says CLRTC_EN next to it, move the jumper onto pins 2-3 and turn on the pc and hold <DEL> down. Then re input your old settings into BIOS, save, turn off pc move the jumper back onto pins 1-2 (default) and turn back on. Should work.