Thanks again for all the help!
Well, using ClockGen scared me at first, got some ugly locks on my machine..
But one of the PLL configs worked for me! I could raise my FSB from 100 to 105, but if I raised more than that, I got a lock. It seems there are components inside that have to be kept at 100MHz. This is strange, because the chipset supports 133/533, the memory supports 166/667, and the CPU is meant to be used at 533. Perhaps the PCI bus is getting overclocked? ClockGen has an option to keep PCIE/AGP/PCI buses speeds unchanged, and I used it, but I´m not sure if it really works.
SetFSB can´t recognize my chipset, and I tried the pinmod (well, I guess the pinmod you refer to it the one with the little wire jumper on the CPU socket) but it didn´t work. I read the pinmod is meant for 400 CPUs to run at 533, which is not my case: my CPU is already 533. Is the pinmod also meant to force a chipset to work at 533??
Anyway, if you guys have any other idea, I´ll try it, but you already helped me a lot!! If the FSB is limited to 400, this is not a big deal, the machine is already running very well the way it is now.
Thanks a lot once again!