Have you tried multiplier only?

That board uses the original KT133 chipset and is very intolerant to increases in bus speed. Set the bus to 100 MHz and the multiplier to 8.5. If it doesn't run, up the voltage. Keep going until you hit the top speed of the chip with your current cooling.

You can also try dropping the multiplier to 6 and increasing the bus speed until you run into trouble. Then, with the highest stable bus speed, start increasing the multiplier.

Don't be afraid to set the voltage to 1.85 V. The drawback to increasing the voltage is heat, so, if you haven't already, download Motherboard Monitor to keep track of your CPU temps.

things to check or keep in mind:

Do you have good contact between the chip and heatsink, and did you use good thermal compound? The "thermal interface materials" on a lot of heatsinks don't perform as well as thermal grease. Don't forget to BE CAREFUL when mounting the heatsink, or you can crack your chip.

How many DIMMs are you using? Going past 1 DIMM usually drops the maximum FSB you can run becasue of a higher load on the memory controller. For instance, my A7V (with the same chipset as your board) will do 109-111 with 1 DIMM, but only 105 with 2.

Try putting a cooler (like a Blue Orb) on the chipset. The standard heatsink used by most manufacturers is pretty crappy, and most of them don't even use thermal grease.

You can also try cooling the clock generator, but with bus speeds around 100 MHz, it probably won't help much.

What kind of hard drive(s) do you have? Maxtors are notorious for crapping out at increased PCI speeds resulting from a slightly overclocked bus.

Good luck.