Apple fixes iPhone 'coma mode' with OS update

Apple has begun distributing an iPhone and iPod Touch software update that fixes several glitches in its recently released iPhone OS 3.1, including a bug that stopped the devices emerging from sleep mode.

When iPhone OS 3.1 was released in early September, users on Apple message boards immediately began reporting problems including reduced battery life, devices freezing or shutting down, and sluggish performance. Some users referred to the problem as "coma mode".

"Basically, it will sleep (or I'll lock it), and then that's it, it won't respond to any input or display anything," one user wrote on an Apple message board. 

According to Apple, iPhone OS 3.1.2, which began to be rolled out on Thursday, fixes "coma mode". The company also said in the statement accompanying the update that other fixed bugs include an issue that could interrupt cellular network services until the user restarts the device, and a flaw that could cause crashes during video streaming.

The update is available via iTunes. The previous software release, 3.1, fixed 10 security flaws, including bugs in the WebKit browser rendering engine that could allow an attacker to run malicious code on the device.

It also introduced features including personalised application recommendations, automated iTunes mixes and an application organiser, and allowed calendar synchronisation with Microsoft Exchange servers.