umm, the point is to try it or not to try it?
Go ahead and see what happens, if it crashes then it crashes. Assuming you are using coolbits if it crashes you can just hold down a key during windows startup and it won't use the oc. Or then just don't check the "apply clock speeds at start up" thingy.
And I'm assuming that 1.29 ghz = 645mhz actual clock speed. (the ram)
If the actual clock speed is 1.29 ghz then I highly doubt it will work.