That's very strange - I just got done playing the Narnia game and all the codes I put in worked just fine.
Don't know what to tell you, but I share your frustration with non working codes. A lot of the codes I got on the cards from our trip won't work, and VMK isn't very helpful about it at all!
This happened to me as well. I'd play Narnia game, get codes, but some of the codes wouldn't work.
I noticed that one of the codes that didn't work was for an ice chair. I already had one in my inventory. I placed the chair in my room then went and got another code for a chair...and it worked that time. I didn't do a lot of testing of this "theory" though. Just thought I'd mention it.