yup, dumb question.... but have you tried turning down the graphic settings to minimum levels? sound off, etc...? I would try to minimize the resources the phone needs to run the app. I have android, but I have the graphics turned down to minimum and all the sounds off. My game damn near always runs smooth, even when others are complaining about crashes and connection issues. I ran insanity all night auto, no problems. Got about 300 runs in over my 5 hour sleep.

I really wish I could help figure out your crashing issues, it's so bizarre.