Twitter was abuzz today with reports of the iPhone glitch that had Europeans sleeping late on a Monday morning.

Some European iPhone owners rolled into work late this morning due to a bug in the phone's operating system that reportedly caused its alarm clock to go off an hour late, as Europe switched from daylight saving time back to GMT.

While the phone's clock changed over correctly, the bug in iOS 4.1 reportedly affected those who had set their alarms to go off at the same time every weekday. "Stupid iPhone's alarm woke me up one hour later today," wrote one Twitter user based in London. "Apparently I wasn't the only one."

Indeed, plenty of European iPhone owners woke up late today to discover that they weren't the only ones who overslept. Twitter and Apple forums were abuzz with iPhone users complaining about the alarm glitch, and swapping suggestions on how to fix it.

"This may seem like a minor issue but I almost missed a flight in the U.K. this morning...not good and nearly very, very costly," wrote a poster to Apple's forums.

In late September and early October, a similar bug hit Australia and New Zealand, where iPhone users who had already "fallen back" an hour lost another one when their iPhones roused them early. Apple has said the beta for iOS 4.2, which goes live this month, fixes the problem.

In the meantime, the iOS4 bug can apparently be avoided by setting one-off alarms rather than pre-setting regular wake-up calls. Or by using one of a number of alarm apps (or a good old-fashioned alarm clock or time-attentive family member).

Of course, plenty of people (mostly those outside of Europe) are finding humor in Europe's mass sleep-in. "The iPhone alarm clock is fine," wrote a Twitter user based in North Carolina. "You're just sleeping wrong."

Meanwhile, while some U.S. iPhone users are reporting that their alarms went off an hour early today, according to Engadget, others are already preparing their late-to-work excuses for next Monday.

Apple did not immediately respond to CNET's request for comment.