HELP! Why Via Apollo 133 overclocks PCI bus?

I have to set a PIII 533 in a Shuttle AV61, but setting bios, I saw a CPU/PCI setting that is, as default, 100/33. Setting it to 133 (the right value for the 533) make change PCI to 44, a value out of range, in fact, my advansys 2930+ does not function (chip failed to initialise). I tried also an adaptec 2940 with no results. My question is: Via 82C693A does support 133FSB cpu? PCI bus is overclocked as a BX mobo? What type of setting I have to do, to make scsi function properly? VIA Apollo Pro 133A have the same problem? Sorry for my english!