Soltek-75KAV 110Mhz+FSB setting problem

[MZperX]

I have a Soltek-75KAV mobo and a 1 Ghz Tbird. This config is run fine at
1.33 Ghz with 1.95V Vcore (12x110Mhz), but when I change the ratio
to 8, 9, 10 or 11 only stable at 110Mhz.
Why I can`t set higher FSB?

Blue core Tbird, 256 Mb NEC PC133 RAM (I always try safest setting no interleave, 100MHz, CAS 3), FOP38