150mhz Bus speed problem

For some reason at 150mhz my ram runs at 112mhz but at 149mhz bus speed the ram runs at 149mhz ... not sure why ? .. also i seem to get problems at 150mhz or 149mhz im not sure why i am using kingmax 2400 ram and i have droped the multiplyer down as low as it goes and core voltage as high as it will go but seems to freeze slowly kinda when at high bus speeds ie like windows media player might stop and mouse stops responding but i can type for a few seconds after then it completely freezes any ideas ?

also done some bench marks

sandra memory
145mhz = 624 int
= 708 Float
150mhz = 528 int
=613 Float

Sandra CPU Benchmark
145mhz = 2447 MIPS
= 1199 MFLOPS
150mhz = 2499 MIPS
=1240 MFLOPS

3dmarks 2001
145mhz = 1912
150mhz = 1836

this is using epox 8kha+ and Duron 800 unlocked .... and a Kyro II 64 meg ( at stock speed) with 2400 kingmax DDR

i would guess that there is a devider on the mobo that kicks in at 150 if thats whats its doing. And after i did the math im sure thats whats happening, the 3/4th devisor for the ram on your mobo is kicking in at taht speed, this is done so you can hit higher fsbs without having to run your ram WAY outa spec, and thus keeping it from working.

Perhaps in the bios theres an option to change/disable the devisor, but im not sure cuz i dont own the board. ask around in the EPoX mobo forum theyd be able to tell ya if thats possible.