I'm running bitcoin-qt version 0.6.2 on windows 7. I'm testing the JSON API. On testnet everything worked as expected, but now - on prodnet - I can't get importprivkey to work. It returns the error message: "Error adding key to wallet" for the private key: 5KBn7DJRBdzdkGEo78n5M8gULKes9FTiWYjr3Ssf3QdAZP7ACGe (Newly generated, not in bitcoin-qt)
The key should be valid. I use walletpassphrase first to unlock the wallet. What am I doing wrong?