Look in your applications or on your battery use screen. There is an application called BIP which is used to synchronize your contacts with certain applications and other accounts from what I understand. I notice on mine that when it shows up in my battery usage screen, my battery life is greatly diminished and will often just die overnight when it has around half battery left at bedtime. It seems that there are times that it's getting hung up and running in the background much more than it should. I have been force closing it when it shows up and my battery life goes back to normal, right, wrong or coincidence aside. It starts back up when needed but closes regularly when not for most of the time. I started noticing the same thing in about the same time frame you mentioned.
