That sounds like a phone issue? How's your memory on your phone (total free, and RAM?).
Is there anythign speacil about your version of the game (where you got it, mod, etc?).
Try deactivating the volume for your device and see if that helps. (and if it does, than that tends to me it's a RAM thing).
Try trouble shooting your device with standard hiccup fixes (clean-up memory, re-start device, etc).