Currently I'm playing in season / career mode. Having started as far down as No. 1954 in the rankings I have worked my way up in about half a game year and now find myself in the ranks somewhere between 100 and 200. Taking a look at the attached file "rankings.jpg" you can see something that has left me wondering if there might be something unsound with the "distribution" of player participation in tournaments. Players ranked from approximately No. 100 down to No. 300 don't seem to be keen to improve or at least maintain their positions as they hardly play any events.
On the other hand, I find that the top players currently are too busy. "Calendar.jpg" shows Rafael Nadal going on collecting bonus miles and titles by flying to South Africa and Brazil after his successful title run at Melbourne. Novak Djokovic, runner-up to Nadal at the Oz Open, also played events during these next two weeks. This is probably more a question of realism than a bug.
Finally a minor issue concerning the player activity overlay where the last line is only partially visible ("activity.jpg").