http://darthsanddroids.net/episodes/0949.html

So ixnay on the... advice-ay, and now we learn that Han is deliberately playing dumb. I think Han actually is the traitor, and is telling Chewie not to talk about Bespin because he's relaying his secrets through Lando to Darth Vader (when we get to Bespin we will find out that Lando and Vader are working together to trap everyone). Han is frozen in carbonite to keep his cover or something.