Continuity puzzling me

I find it rather weird that in Attack of the Clones, R2D2 and C3PO were both on Tatooine at the place where Anakins mom was buried. Sorry, I don't know the name of the place. You know, it looks like a sand igloo and there's a big round hole in the ground.

In episode IV when R2D2 and C3PO are brought there by the Jawas, they don't exclaim 'Hey, we've been here before, remember us?!' I think in Attack of the Clones, they shouldn't have spent any time there unless I'm missing something. Perhaps in episode III they get their memories erased.

Other things: Those tall, thin creatures on Camino are really cool. Is it perpetually raining on Camino? Was Sipher Dius (sp?) in Phantom Menace? If he was, I would like to know what he looked like and how he died.

There's a 20 year gap bewtween Episode III and Episode IV, either ...

1. The droids had a few owners and memory wipes over the years.

2. The droids were sent with baby Leia, but had their memories wiped to protect her (and Luke's) real identity.

We'll just have to wait to see what Episode III might explain.

Not sure about theses ones ... yet!

They reminded me of those creatures from 'A.I.'