I have the HD version running on iOS 5. The game crashes OFTEN when starting an adventure and sometimes when ending an adventure. It makes the game nearly unplayable.

VERY frustrating to play through the same adventure and win 3 times only to have it crash before it saves your progress. Of course, it managed to make it through without crashing the time I failed.

I did notice that the game does not seem to crash when I was out of range of a wireless network. I put the device into airplane mode when I was back home and the game still continued to crash (which doesn't make a lot of sense).

I believe the game has a serious issue with the new notification center in ios5. I play almost exclusively on my Mac for this very reason... and yes, I had to pay for the privilege of getting a version of the game I can actually play.

So, perhaps, you are right, turning the wireless off may help, though I would have thought that airplane mode would have the same beneficial effect if so.