The explanatory text for Maximum number of concurrent games before preventing challenges in Your Settings is under the bit that says Receive email move notifications for your opponents' moves and not where it should be.

Just a small thing No. 2

After finding a batch of players between a certain rating using "Find Player", when I go to challenge one of them the new game screen comes up but the little black check dot is in the "Open Invite" bit. The player's name of who I want to challenge is in the "Challenge Player" or whatever it says bit, but the check dot isn't. If people aren't paying attention they may be creating a load of open invite games instead of sending through challenges to particular peeps.