On the Andreev question, I suppose it was simply a correction due to a mistake. As I posted above (Mar 17), ATP had put in that correction pretty soon after the lists came out. He was simply added to the initial list at Barcelona, and then they listed him as a withdrawal at Houston. Remember that no player complains about a withdrawal - so ATP does not send out a correction notice in that case. They sent out a correction on Barcelona, as a player was added in and somebody fell out by a spot.
I assume this was not Andreev's fault, and so ATP corrected the little mistake. Andreev must have never entered Houston, and so technically his being listed as a withdrawal there was just a correction on the list and not a withdrawal by him.