A few Star Defense bugs

The first bugs were encountered on an original launch iPhone. On the later planets I would experience a bit of lag when I was in the final rounds. I found a temporary fix to this problem which was to turn the volume completely off. If I didn't do this, the bug would cause the game to quit on me. I had this happen to me TWICE. Which brings me to ask: why not provide an auto-save feature like the kind found in Rolando? *Edit: There is an auto-save feature, just not when the game force quits.* Anyways, when I got my new iPhone 3G S, I wanted to test out this game because of how awesome it is! The lag was gone because of the 3G S's greater speed, but a new bug popped up. I was on one of the later planets,
about 50 rounds done (in a 60 round game) when I get a notification that my battery is at 20%. I think, ok I can finish up this game. Wrong! The game quits on me and takes me to the home screen! >:( Thats a total of 3 quits on me when I've neared the end of a game. Disappointing and frustrating. Please fix this because this truly is a great game.