Bad motherboard?

[EL-Blixten]

Cant it be the motherbord who stops my OC?
I´ve been running my Celeron 566/850 @ 1.85V for about 6 months rock solid, but no more. And I´ve tried a Celeron 600/900 @ 1.75V also 100% stable but i cant getting over 100mhz fsb. I´ve also tried a PIII 600/800 @ 133mhz fsb, can it be some strange thing with the fsb between 100 and 133 that is not stable or what is wrong? Please help me
Sorry my bad english
I´ve been using Abit BE6-2 Rev 1.2 with the "UH" BIOS

 

[wild_andy_c]

You don't mention what kind of memory you have or the cooling medium used - these could well be defining factors

 

[EL-Blixten]

I use Alpha PEP66, 22C idle
And my memory is Samsung PC100, tried @ 133MHz FSB (3,3,3)
It cant be these things who stop me, i should getting at least a few more MHz??