When I am running my application on my device, it asks for system username and password again and again. Previously, I was running on iphone, it asked for first time only.

When I am running my application on my device, it asks for system username and password again and again. Previously, I was running on iphone, it asked for first time only.

Maybe some keys for your provision profiles placed in System keychain? In this case you should move them to another keychain. In application Applications/Utilities/Keychain Access , move them to the "login" keychain.
You should move them to another keychain. In application Applications/Utilities/Keychain Access , move them to the "login" keychain. Enter your credentials, you problem will be resolved.