iPhone in reboot loop after restore/reconfigure

My trusty iPhone has developed an annoying habit of rebooting every few minutes - happens while the phone is in use, on charge, connected to the PC. battery appears OK and it is fully charging.

Unit has worked flawlessly since I got it and my daughter has claimed it since my Blackberry went into use. She had used it for a few months with out issue but this weekend we did a restore and and transferred her ipod over to the iPhone and enabled cloud sync and now it has this reboot loop happening.