From Return of the Jedi (emphasis mine):
A lonely, windswept road meanders through the desolate Tatooine terrain. We HEAR a familiar BEEPING and a distinctive reply before catching sight of ARTOO-DETOO and SEE-THREEPIO, making their way along the road toward the ominous palace of Jabba the Hutt.
THREEPIO: Of course I'm worried. And you should be, too. Lando Calrissian and poor Chewbacca never returned from this awful place.
We know that Lando disguised himself as a guard. Chewbacca, however, didn't come to Jabba's palace until later, when Leia brought him. There's nothing to indicate he was there earlier, and if he was, it would be odd that Jabba didn't mention this when he was later brought to him.
Is there some deleted scene or EU work that explains the apparent discrepancy?