It is just the limitation of the chipset itself, its not CPU related, the KT133 were not the best chipset around, the KT133A on the other hand gave a really great boost to AMD FSB O/Cing, my mobo which is the A7V133 can go in theory upto 200MHz, but I'll be limited by the PCI & AGP dividers because there's only 1/4 max divider, so I can't go higher, my cards would be the ones holding me back, in your case it also could be a PCI card or a vid card that's holding u back, try removing every card from the PC except the vid card and try 121, if its a no go, then you are propably stuck. And reaching these FSB speeds with a KT133 is nothing really to complain about, your only option would be to upgrade the motherboard, and prolly the mem as well to some nice DDR board