LOL, that is true. And just about everyone else in Jabba's Palace were armed. Well, I guess when they captured Luke they probably checked him for weapons.

Scruffy said:
Z6PO said:
(remember, in episode IV, he doesn't know the princess when R2 plays the hologram message, but earlier in the movie he says "there will be no escape for the princess"... I wonder if he may have some memory malfunction...)

On the contrary, Threepio remembers everything. Perfectly. But he is a protocol droid, in the service of the Royal Family of Alderaan, and it would be against his programming to disclose their secrets to common farmboys. Or the secrets of his previous masters. It just wouldn't be proper.

Yeah, Scruffy is right, his memory is fine. Watch that scene again, it has always felt to me like he was protecting the stubborn Artoo more than watching out for the Princess. He obviously didn't know what the message was, because he had never seen it nor did he see her record it in front of Artoo. As soon as Luke leaves the room Threepio drops his polite voice, turns to Artoo, and scolds his saying, "Just you consider replaying that message for him!"

In Shadows of the Empire, it explains that Luke purposfully keeps Threepio in the dark about the actual plan.

He is not the smartest droid, but his memory is just fine.