Afaik when you switch the jumper on that mobo from 100 -> 133, your cpu must be able to post at 133 fsb at it's default multipier.
eg: if you have a 1ghz athlon (100x10) and you wanna do a 997.5/1G (133x7.5) then your cpu MUST be able to post at (133x10) cause the mobo starts off at that and THEN applies the settings that you have choosen. One way to get around this is to use the pencil trick and make your cpu a 600 or 550 making the mobo think it's default multipier is 6/5.5 and it will boot allright at 133x6 and THEN you can change the setting to whatever you want in bios.
This is my understanding, and i might be wrong. I own a 8kta3 and this is what i did to get around it.
Later,