PenguinKing said:
As far as I can recall, throughout the whole original trilogy, Vader only ever saw R2D2 when he was in the back of Luke's X-Wing, and he never laid eyes on C3P0 at all. Correct me if I'm wrong, but...
- Sir Bob.
Sure he did, in Empire. The carbon freeze chamber, when Threepio was hanging from Chewbacca's back. Not that it really matters... Threepio's name wasn't mentioned, so there's no reason Vader would think it was the droid he built as a child, unless MAYBE he recognized the voice. And somehow I doubt that all protocol driods have unique voices.