What about this White 6?
I didn't see it at first, but this does kill White. My apology for generating this erroneous "Failure" file. For the benefit of the other weak kyus --
Eventually, White will have to capture three stones (at a). When she does, Black must ThrowIn a nakade (at the Black stone marked with a square). White will be reduced to one eye. (There is no chance to make an eye at with b or c. If White plays one, Black plays the other, which keeps this as a FalseEye at best.)
Again, my apology... -- TakeNGive 11k