So, the other day I finally got around to backing up my Witcher 2 copy here on GOG (I know, I'm quite late) and also noticed I could get a free backup copy of the original Witcher, which I also own. Here's the issue, the product key simply won't work. I've tried numerous times and made sure to carefully read and reread the code again and again. I've also tried the usual tactics like reversing certain characters that often get confused (i.e. O, 0), but to no avail. To make it clear, the key I'm entering is located on the inside of the front cover of the game manual and is listed as a registration key for use at the now dead URL www.thewitcher.com/registration. Is this the correct key to enter? I've scanned over the box and all included documents numerous times but can't find any other product key.

Figured I'd throw this post up and see if I'm missing anything obvious before I make a request for a new product key via the official site. Thanks for any help.

Are you entering it here?
http://www.gog.com/witcher2/backup

Yes, that's where I'm entering the key at.