redsamurai said:old kenobi said he never owned an r2 unit. That maybe true, but surely he would have remembered r2. Wasn't r2 qwigong's?? He would at least remember that that he used to know an r2 unit. And in a "new hope", artoo was telling luke that he was looking for his old master. I think willow might be right, there's no ryme or reason to this........it's just inconsistent.
Like I said, the R2 units were a dime a dozen. He may have looked at R2 and thought to himself "These things were everywhere back in the day" much the same as you and I would think when looking at a Mustang GT from the mid 80's.
Yes, Qui-Gon Jinn owned R2, but Obi-Wan never officially took ownership once Qui-Gon fell victim to the evil Darth Maul, therefore once again reinforcing what Obi-Wan said in episode IV about not recalling the ownership of a droid.
R2 may have been telling Luke he was looking for his old master because someone in the Imperial IT department (probably a distant relative of Pintoca) screwed up while erasing the droids memories. 3P0 was successfully zapped, while R2 still had some dingle-berries.