I've been playing fieldrunners HD all day now; it sometimes loads to a black screen but when iit actually loads the map its pretty much flawless. Hopefully the dev works these iissues out as they are pretty minor (except the part where I cant play the game heh)
Glad it's (mostly) working for you. Spent most of the playtime today on medium. Never had problems with black screens but did notice that during some of the crazier waves I would lose the sound effects. Music continued to play though.
Funny enough, I am getting the occasional black screen with today's free app, Age of Zombies. When it happens, I have to hit the Home button on my tablet then reload the game to get it to play.
But I can't complain since they were free.