Apple's iOS 5 mobile operating system update has left some users with temporarily bricked devices or data loss.
iPhone and iPad users flocked to Apple's iTunes to download updates, with some Twitter reports suggesting the download took up to four hours.
The latest incarnation of the OS includes new features, such as access to Apple's iCloud services, a new messaging service and over-the-air update capabilities.
But with millions rushing to download the software, the servers struggled.
“Installing new iTunes took 30 mins. Downloading iOS 5? 30 years by looks of it. It's showing 20 mins remaining for past hour and half,” tweeted WannabeSW, echoing widespread concerns over slow downloads.
Tortuous updates were easier to deal with than the rash of bricked devices, which appear to have been caused by failed upgrades and a subsequent failure to reconnect to the servers to restore the iPad/iPhone.
“Seriously not amused at how iOS 5 not only bricked my phone but also removed all my contacts,” posted Sheryl Camp, one of many reporting data loss problems.
“Apple has now bricked my iPhone...and the servers are overloaded so I can't update,” tweeted Matt Asay. “This infatuation with Apple hurts today. Mucho.”
Other users have complained of apps being wiped from devices during the upgrade process, and not always being restored in working order.