I've been kicked out of the game a few times today for some reason. It started either today or last night and I haven't changed anything other than upgrade to 4.2 in the iPhone and upgrade to 1.6 for the app. I believe my ping was below 500 each time as well.

My screen just goes black temporarily and then I'm on the home page. One time after it happened and I logged back into the game, I was without background music for awhile. It didn't come back until I went into the menus where there was music and then exited the menus.