Hi David, something like that happened to me yesterday, shortly after update. I was using Samsung Galaxy SIII mini, I came to the mentioned character (Erhardt) and when I chose invitation to the pub, application dissapeared and write me down in Czech: The application crashed. After that I restarted mobile phone and everything works fine again.
So I guess, there should be problem with mobile phone, when you are using much more app then one .
By the way, I like the game, especially that concept with free world and many options you can choose in dialogues.