well, i can't comment on the KT7 too much, as i've never used one. but i am assuming the bios isn't that much different from the KT7A. they're essentially the same mobo. i have access to multiplier settings in mine running the full gamut.
as far as opening up the bridges, you shouldn't have to worry about any bridges other than the L1 bridges on the processor. once those are closed, you'll completely unlock the multiplier. You're using an Athlon B or C? just checking to make sure. if you're talking about 133 FSB, then it's the C. the text on the core should tell you exactly what speed your processor is supposed to be, and what FSB it can run at. i may be completely off track, because all this talk of other bridges is foreign to me.
it doesn't matter what AMD set the multiplier to originally. once you unlock it (with the L1 bridges), you should have full access to multiplier numbers increasing in .5 increments. if you don't have this, it's probably a bios issue. at least that would be my first thought. but since you're running the newest one, this shouldn't be it.
once you go into the bios, go to SoftMENU III. when you choose processor speed, go all the way to the top of the menu that pops up and choose "user select". then you will be able to go and set the multiplier and FSB independently. you can choose whatever FSB and multiplier you want. you'l even have the option of increasing the CPU FSB independently of the southbridge (i think that's the correct term for FSB for the PCI and vid card and such).
again, i apologize if this isn't helpful, but i don't entirely understand your problem. but lets keep working it until we figure it out, ok?!? let me know how it turns out
allgoodpeople
"It's a dog eat dog world, and I'm wearing milkbone underwear."