I have a jailbroken iPhone 4S on iOS 5.1.1. Yesterday i was updating the cydia apps / tweaks and after one of the apps (Installous) got updated, it told me to reboot the device, i usually expect either a "Restart Springboard" or "Return to Cydia" but reboot was new to me. Anyways at this point, one does not have any option, so i pressed the reboot device option and after that my iPhone went into the repsring loop. Before that app, i had updated CameraTweak and Action Menu tweaks so i am not sure what might have caused the problem. I searched on the net for a fix (without restoring) and found that i should press power and home button together until apple logo comes and then release power button and then screen will be blank and iPhone will boot. In my cases the phone did not boot by itself so i pressed the power button and it did reboot fine and everything worked. How can i avoid these respring loops in future as we tend to update cydia apps as and when updates arrive.