Can you change the vcore on an a7a266?

There is a jumper that lets you change between automatic or manual determination of the vcore, but no matter which position I put the jumper in, it's locked in bios. There are no additional jumpers or switches to change it anywhere. Any ideas how to change it?

sorry i dont know the board hope this helps

http://www.ocworkbench.com/hardware/asus/a7a266/a7a266reviewp5.htm