This hypothesis might be too wild and crazy, you know, "out there", but when Padme died of a broken heart after being choked in the throat, Darth Vider was given to the false impression that his kid(s) also died? Then the Rebel Alliance buried Pad-me with Pad-ding to enforce this perception. Anyway, I got this vibe that Vader had gone all Ice Cube at that stage and all he could see was Vader in court, paying a gang on child support. Not to mention he was already a child abuser - what with the lightsabering of apprentice Jedis to death - so he was all too relieved that the rugrats were forked off onto old Uncle Owen leaving him free to ravage universe.
[Edited 11/12/08 15:29pm]