Overheating issues with Apple's highly-anticipated iPhone 5 are causing a delay with the product, according to a report.

A report by Soho.com, a Chinese Web site, reported that Apple's engineering team is having difficulty keeping the A5 chip inside the chassis of the un-released iPhone 5 cool. The report suggests Apple will release the iPhone 4S this fall instead, delaying the anticipated release of the iPhone 5, intended to be a next generation smartphone taking a radical jump from current iPhone models.

The iPhone 5 prototype is smaller, making cooling for the unit more challenging. Reports earlier had said Apple was in the process of ordering manufacturing parts to begin production of the iPhone 5 but that the overheating issue has caused a change in plans.

Apple faced a similar problem in 2009 with the release of its iPhone 3GS. Reports surfaced shortly after the iPhone 3GS was released in the summer of 2009 from customers complaining that their unit was regularly overheating. The iPhone 3GS was released in mid-June 2009 and customer reports were piling up on Web chats and blogs within two weeks.

Some customers at that time said their iPhone 3GS' was literally too hot to handle.

Apple was silent on the over-heating issue for weeks in 2009, but the company finally addressed the consumer complaint publicly by blaming it on the weather and other user oddities.

Apple had posted on one of the company's support sites that the iPhone has a safety feature that warns users the device is becoming too hot. The company said leaving the handset in a car may cause the unit to overheat when it is left in direct sunlight for prolonged periods, or when the smartphone's iPod function is used in direct sunlight.

But the issue Apple may be facing with the iPhone 5, which was rumored just a month ago for release in September, is believed to more serious than it faced with the iPhone 3GS launch. The talk of an overheating problem is gaining traction as one stock trader told CNBC she's bullish on Apple long-term, but wary short-term.

Too many things could go wrong, she says. There's chatter that the new iPhone overheats.

The theory if the report from Soho.com is on target is that Cupertino, California-based Apple, which manufactures its iPhones in China, cannot launch its new iPhone 5 because of the overheating problem with the A5 chipset used in the phone, and the company will take its time instead to iron out the problem, releasing instead this fall the iPhone 4S, a less radically-changed update.

Apple is said to be considering transitioning for the iPhone 5 from the A5 chipset to a 28-nanometer manufacturing process with the A6 chip.

Apple is the global leader in smartphone sales. The company has sold more than 100 million iPhone's since launching the product in 2007.