kr7a multiplier problem

I just got an xp 1800+ (JIUHB/DUT3C), and an abit kr7a (no raid) mobo. the proc does 2.2ghz on air. the thing that is ****ing me off is that I can only select a multipier up to 12.5x. If I select a 13x multipplier, the proc is reset to its default 11.5 multipplier. Does anyone have any suggestion of how to fix/ bypass this. thanx

abit kr7a (non raid) mobo
1800+
256mb pc2100
10.2gb hd
350w psu

almost forgot, proc @ 1.725v setting v hight doesn't help

Aren't the upper multis locked on that proc.