Corrected entry: In the scene where Uncle Owen is speaking to C-3PO about whether or not he can talk to the machinery on the farm (I think they were called evaporators) there is an interesting nod to the first films. C-3PO replies that his first job was working with machines quite similar to Owens. Indeed it was, in fact they were probably identical given Owen was his first employer also. Nice little touch with about twenty years of foresight from George Lucas.
Corrected entry: When Owen talks to Beru in the morning, she says, "I think so.", but her lips hardly move. (00:26:30)
Corrected entry: In the first few scenes where we see C3PO and R2D2 on the rebel blockade runner in the beginning of the movie, C3PO says "There'll be no escape for the Princess this time." implying he is familiar with the princess. However, on Tatooine when R2D2 is playing back Princess Leia's hologram for Luke and Luke asks who she is, C3PO replies, "I'm afraid I'm not quite sure, sir. I think she was a passenger on our last voyage. A person of some importance, sir - I believe."
Corrected entry: When the Death star blows up, it surprisingly has no debris, even though two proton torpedoes went down the exhaust port, there still should have been at least a little debris, the blast wouldn't have completely atomised the whole Death star.
Corrected entry: If the Death Star did take 18-20 years to build, then it would impossible for them to finish the second Death Star, as there wasn't 18-20 years in between episodes V and VI.
Corrected entry: When the Millennium Falcon escapes from the Death Star, Darth Vader only let it go so it would give away the location of the Rebel base. So why would Ties attack it? They're taking pretty big chunks out of the ship (It seems doubtful that Grand Moff Tarkin would want to risk blowing up the Falcon, given the extremes he has already gone to to find the base), and even if they were already out there, wouldn't someone try to contact them to allow the ship to pass?