I realize this is REALLY splitting hairs but it's something I set out to watch for in ROTS. In ANH when Luke refers to Kenobi as Obi Wan, Ben's response is "I haven't gone by that name since oh...before you were born." In ROTS, FOLLOWING the birth of the twins, Padme whispers to Kenobi: "Obi Wan...there's still good in him." So, technically he lied to Luke because he HAD gone by that name at least once that we know of after Luke was born. If there is a "nitpicking" hall of fame then this factoid will no doubt soon festoon its walls...But hey, you asked.