Kinda. Originally, Jabba was played by a man. Harrison Ford plays the scene interacting with the actor. At some point in the shot, Solo walks behind Jabba. Now, when they came to add the CGI blubbery version of Jabba, they realised that where Solo walks, Jabba's tail would be in the way. They therefore clumsily move Han Solo up and down to make it look at though he's walking directly over the tail.
May I might add that the scene is a totally redundant replay of the information we find out in the cantina and really irks me (although not as much as Greedo firing first, of course). Leave the damn film alone, Lucas!