Try to use User ID instead of Username if it does not work. A typical reason of this is the character '[' and ']', use User ID if your name contain these characters.
A smaller value means you need to play relatively more maps to bump your rank/pp compared to people having a higher value, vice versa.
Sun Nov 8 11:38:01 CST 2015: New algorithm! Time to achieve top ranks is now taken into account.