cbeast -
Probably totally irrelevant, but I ran into a similar situation with Bitcoin QT.
Despite copying and pasting (versus manually typing) my private key passphrase every time, from a source document, I woke up one morning to a wallet that was rejecting that passphrase.
I had a lot. And I mean a lot ... of Bitcoins in that wallet. It was stored offline.
Different issue, but strange solution.
I went through every single character and tried its inverse. Like this:
Known and quadruple verified passphrase which was copied and pasted:
uPjKmN
Tried:
UPjKmN
then...
upjKmN
then...
uPjkmN
then...
uPjKmn
Switching the case of each character each time i re-tried.
and that worked.
It shouldn't have.
Immediately got rid of QT and put all my sh*t on paper wallets.
ummm... that's actually very similar to my passphrase. It was THAT simple, though much longer. And yes, it was over 100 BTC and they are not all mine.