A freshly released Apple software update disables iPhones hacked to let users install custom programs or use telecom carriers other than the authorised one, AT&T.

Renegade software wizards that devised ways to break into iPhone's jealously guarded inner workings and sever an exclusive link to AT&T are trying to work their magic anew on Apple's software upgrade.

Engineers at iPhoneSimFree said on Friday in a website posting that they tested the iPhone update and found the devices remain unlocked and operable as long as they use an original AT&T chip known as a "subscriber identity module" (SIM) card.

"Unfortunately, currently there is no way to jailbreak/reactivate the phone for use with a SIM card other than the original AT&T card," an iPhoneSimFree posting said.

"We are all looking into the jailbreak issue as it affects us all."

Without the optional update, hacked iPhones can be made to work with SIM cards for other service providers.

Thousands of open source developers who have put "cumulative tens of thousands" of hours into custom software applications and tools now have no way to get them onto updated iPhones, according to iPhoneSimFree.

Apple did not return an AFP request for comment.

Early in the week the iconic California-based company issued a warning that its iPhone update, the first since the devices went on sale in the United States in June, could disable phones hacked to link to users other than AT&T.

The US telecom giant is the sole iPhone service provider authorised by Apple in the United States.

The iPhone update patches holes in security and enables devices to connect to an iTunes music store designed for wireless connections from mobile devices.

Apple this month cut the price of the popular eight-gigabyte iPhones to by a third to $US399. Apple is to begin selling iPhones in Europe in November.

AFP

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