Wondering how a player with rating of 2150 is playing me in a tourney of under 1900.  He or she also had a rating as high as 2300 at one point with nearly 200 games plated ?

This tournament   http://www.chess.com/tournament/chessamerica-2010-under-1900  started 2010 03 30. At that time your opponent's rating was within the registration limit. There is no obligation for your opponent to withdraw.

You should expect some players' ratings to exceed the maximum in every tournament with a maximum rating, and be pleasantly surprised when it does not.

Coincidentally, you are this opponent....