Help Importing Litecoin Private Keys

[No_2]

Trying to redeem a private key at the Litecoin QT Debug Console and I get the following message:

    Error adding key to wallet (code -4)

I have done this with the wallet decrypted using 'walletpassphrase'. I have also scanned the 2D barcode for this key to make sure I'm not mistyping anything.

I am using version 0.8.3.7 on Windows 7.

Can anyone tell me what I might be doing wrong..?

[lukemarshall]

Make sure that your wallet is unlocked... if it's not use the walletpassphrase and a time alotment under the debug screen to unlock it and add the private key.

[No_2]

Make sure that your wallet is unlocked... if it's not use the walletpassphrase and a time alotment under the debug screen to unlock it and add the private key.

Yup done that...

I have done this with the wallet decrypted using 'walletpassphrase'. I have also scanned the 2D barcode for this key to make sure I'm not mistyping anything.

[No_2]

I'm importing from the following address:

    LhkcvamWUuGFbUvhGraAC9pKdpMDHku2ZC

See here:

    http://block-explorer.com/address/LhkcvamWUuGFbUvhGraAC9pKdpMDHku2ZC

The balance is 0.1LTC. I'm assuming there are no restrictions on how much one can import?

Going to try importing on a different LTC client later today when I'm at a different machine.

Is there a list of error codes anyone knows of they can point me at?