Did I read somewhere that mtgox will let you import private keys? You could try that, see if that works... or you crash them.
Heh. I didn't crash MtGox, but I tried the privkey there, and blockchain.info. Both showed the coins, but could not send.
Another weird data point. When testing on an unencrypted 4.1 wallet, Jackjack's pywallet pulls a different key that reimports to a different address (with no coins). Joric's pywallet extracts and imports the correct key without issue. Perhaps that is just a bug or incompatibility in the older pywallet code.