I don't know if there are any plans to include the same functionality of a registry cleaner in the full installed version of OneCare. Since it hasn't appeared yet and we just got the new 2.0 beta, I'm of the opinion that they decided not to include it. There's been lots of discussions regarding registry cleaning and the inherent risks and benefits, so I won't repeat it here.
However, if you are encountering a script error with the online scanner, you should take that issue to the forums dedicated to the free online Safety scanner -
http://boards.live.com/safetyboards/board.aspx?BoardID=225
-steve