I am having the same issue along with a couple of others: terrible lag and the Pi being slow to recognize the controller (PS3 over USB). In my research today, the suggested reason for the “other” issues was lack of power over the USB ports. It dawned on me that it was suggested to get a 2 amp power supply, but I had a 1 amp one laying around so I used it. I have seen similar problems before with other electronics and underpowered adapters so it does seem possible. What is the rating on yours?