app crashes if I restart the device and launch it again
===

iPhone app that I'm working on runs fine but it starts crashing if I restart the device and launch it again. 
After that if I connect the device to my mac machine it works fine.(without even building the app again)

I am using

XCode- 4.2

device- iPhone4 

device OS version- 5.0.1(9A405)

app deployment target: 5.0 

iOS SDK: 5.0

I can't even check for any log as it crashes after restart.

Where do I look for bugs? Please advice.
