PvZ input lag

I have a very capable computer that I just built. I can play any other game fine. This game has terrible input lag. Sometimes as soon as I enter a game, sometimes it takes a couple minutes. It gets so bad that I can make a lot of moves, then let go of the mouse and the character continues to move for another 2-5 seconds. As far as my pc, I have a windows exp score of 7.8. So it is not my system. Amd CPU at 4.7gig, EVGA gtx 970 ssc GPU, and 8 gigs of ram. Thank you for any help you can offer on this problem.