While at work this morning, I heard one of my work colleagues complaining about its iPhone alarm going off an hour late. The first thing I thought of was that the phone must have been manually updated and then updated itself automatically at the DST switch. I didn't give much thought until I heard about the problem on the news.
Apparently, Apple had created a fix for this issue, but obviosuly hadn't released the update in time! Interestingly, while the bug caused the alarm to go off early in the UK/Ireland (and probably other EU countries), it went off an hour early in the US going by the PC World story.
One thing's for sure - Never rely solely on a mobile phone to wake up! :disagree: I have a regular digital alarm as backup. If I have something important in the morning, I use the trusty wind-up and place it out of reach from the bed.
If the battery runs out on the phone, the alarm will not go off and I have already been caught out before. My last phone (Nokia 6300) actually had a worse bug, where if the battery was flat at the time the alarm would ring, the alarm would disable itself! This meant that if the alarm was not re-enabled when the phone was plugged in, the alarm would not go off the following day even with a full battery.