In spite of Apple claims that the iPhone 4's glass is 30 times harder than plastic and less prone to breakage, a Sydney iPhone repair shop says that it received its first broken unit the day the smartphone was released.

iPhone 4 buyers are advised to be careful since dropped phones are not covered under warranty and repair costs are high.

In an interview with the Sydnet Morning Herald, Alex McCredie, director of Fixpod in Sydney, says that the model is just as, if not more, fragile than previous models.

"We received our first iPhone 4 screen repair request the day after it was released. It was not unexpected, given that the iPhone 4 does not have the protective chrome bezel around the screen that the earlier models have, and has glass on the front and back," McCredie said.

He said that dropped phones are not covered by Apple under warranty and that the cost to repair the unit is more expensive than the iPhone 3G and 3GS.

"Repairs are likely to remain more expensive than for iPhone 3G and 3GS as the front glass and touch sensor are laminated to the LCD and cannot be replaced separately," he said.

"This will make for a clearer screen however, as dust won't be able to get between the front glass and the LCD."

Apple says that the iPhone 4's "aluminosilicate glass" is the same type of glass used in the windshields of helicopters and high-speed trains.

"Chemically strengthened to be 20 times stiffer and 30 times harder than plastic, the glass is ultradurable and more scratch resistant than ever," Apple says.