Originally he was using an invalid key that may been generated incorrectly by the paper wallet generator.
You should try scan the qr code to see if that solves your problem.
(Note: I could be reading this wrong...I'm actually having the same problem but don't have a way to scan my code)
Thanks.
I use QuickMark on my desktop to scan QR Codes.... if that helps you.
http://www.quickmark.com.tw/
I finally managed to get my keys to import using the info here... https://litecointalk.org/index.php?topic=19218.0
There were 2 issues I experienced...
1. my private key needed to be decrypted (with the BIP38 password I set it up with) before it would be accepted by the wallet.
2. the QT wallet kept freezing & failing, so I used the stand-alone Electrum LTC wallet which worked instantly.