Bobocop said:
I know Han said Jabba put a price on his head, and why not collect a double bounty, from the Empire and then from Jabba? Tatooine is the logical place to start looking, and it was their rendezvous point, after all. It seems they knew he would be taken there; I just don't remember if Vader or Boba ever mentioned Jabba...
Vader says "You may take Captain Solo to Jabba the Hutt after I have Skywalker" to Boba.