With improved cleaners, as for the painting of the outer edge, I found little benefit, which again suggests that it is not disc wobble.
That would make it harder to explain. The reflections then would need to be enough for the CD player to resort to interpolating some unread data. ( which does occur on badly damaged/scratched CD's but should not be the normal way of things )
For more info to see how CD players do a lot of checking on what they read see this. It is kind of like the game Mastermind board game or Cluedo - after a while you have enough redundant data to be sure what you have hidden from view (or in teh case of a CD what data was misread). For sure audio CD's do not have as much redundant data for cross checking accuracy as a CD-ROM disc(where a single error could mean that software will not run on the computer) - but it should be more than enough to weed out errors from misread bits due to odd scattered reflections of light...