XP-M 2400+ weird question

I bought a new XP-M 2400+(AQYHA) from New egg
when I tried to OC, it allows me for 2.2GHz (166*13.5) and everything runs fine, stable for Prime95...

But for 200MHz FSB, it is quite stable at 200*9.5, but won't boot at all at 200*10. Very weird, and I tried CPU voltage, Memory Voltage and everything. It just won't boot.

Configuration:
Abit NF7 Rev-2 with newest BIOS
XP-M 2400+ (AQYHA 0415) w/ Volcano 7+
1x PNY PC2700 512MB (Bravo chips, stable at 210Mhz)
Maxtor 160GB ATA133
ATI Radeon 8500 AGP4x (150/150)
CDRW
Antec 300W Solution Series

Anyone knows how to open my 200*10 secret chamber? any suggestion is appreciated.

that chip should be able to do 2ghz at stock volts... mobiles are cream of the crop chips for the most part. anyways, i guess i would try 10.5 etc and see what happens. may have to bump up the volts slightly. could be just another odd chip that either a) will oc well when it wants to, or b) a bad apple.

"newest BIOS", do you mean 24?

if so, go back a notch, 24 restricts fsb for whatever reason...