"Owners of Apple's iPhone are being warned to manually reset the alarms on their smartphones as the clocks go back this weekend amid warnings a glitch in the gadget will fail to set the alarm clock off on time.
Users in Australia and Europe have already taken to the internet in outrage after their alarms went off an hour later than they should have when the clocks went back there last weekend.
The same problem is set to happen in the U.S. as the clocks fall back at 2am on Sunday morning.
Today Apple spokesman Natalie Harrison said the company is advising customers to set non-repeating alarms for now, and reset after November 7 to solve the issue."
SOURCE:
(http://www.dailymail.co.uk/sciencete...=feeds-newsxml)
Also, this has been happening on 4.1 firmware.