Dempsey wants to move to Liverpool and is annoyed that Fulham haven't just caved into his demands and let him leave immediately for free. Martin Jol doesn't want to sell him because he's good at football and that's about as complicated as this gets.
To be fair, I don't blame him for not wanting to go into Martin Jol's office. He looks like he'd try and tell you stories about his shed while telling you about the great meal he had in this restaurant the other night. "It wash called nandosh I think - very delishioush"