Yeah, the links to anybody's page who has a dash or underdash in their username don't work. I wouldn't be surprised if there's other characters that mess up too. But at least they can still log in. 
A bug with nicknames using some characters
Sort:
http://www.chess.com/echess/game?id=61262676
If you click to the nickname of the user "-Rigden-", you don't see his profile, but land to another page.
Please fix it :)