The mail problem!
Santa is speaking to his psychiatrist.
Santa: "I`m on the road a lot, and my clients are complaining that they can never reach me."
Psychiatrist: "Don`t you have a phone in your car?"
Santa: "That`s a little too expensive, so I did the next best thing. I put a mailbox in my car."
Psychiatrist: "Uh ... How`s that working?"
Santa: "Actually, I haven`t gotten any letters yet."
Psychiatrist: "And why do you think that is?" Santa: "I figured it`s because when I`m driving around, my zip code keeps changing."