I just played a normal game and solo queued. We won in just under 40 min and I only received 95 IP, it was also my first win of the day and I haven't queue dodged at all. Bug?
Next game you play it should pop up with a thingy saying you've recived a bonus from a previous game played, and that'll be your win bonus from that game.
One of your leaves may have been recent enough that your non-leave bonus is not the max of 23 bonus IP.
© 2014 Riot Games, Inc. All rights reserved. Riot Games, League of Legends and PvP.net are trademarks, services marks, or registered trademarks of Riot Games, Inc.