Hmmm, you could be right. From Anand's, review:
<< But again, as we mentioned before, all of the Athlons that have been released prior to the AMD 760 chipset all use the 100MHz DDR FSB, and chances are that a 1.2GHz Athlon will not want to work at 12.0 x 133MHz.
>>
You could try to underclock the multiplier to get the FSB to 133, as it is not limited by the AMD 760 chipset, as it was with the KT-133. I know my friend has a P2 multiplier underclocked from 4 to 3, and overclocked the FSB to 100, for the same speed (obviously more performance though). It's worth a shot, at any rate. What speed cpu do you have?