Sorry to bring this old arguement up again, but I just thought of a reason for Boba to be in RotJ:

Maybe have Jabba say something like "Contact Fett that his bounty will be executed, I'm sure he'd want to see the show" to Bib Fortuna after he tells Han and Luke they'll be fed to the Sarlaac (While everyone's still in the Palace) and never show Boba in the Palace, but show him on the Sail Barge. But thats just an idea....

Also, someone please remove C-3PO's "Ric Olié" dialogue, like "Theres Captian Solo, and he's still frozen in Carbonite". Those lines are just painful to listen too....