By Kasper Jade

Published: 12:00 AM EST

Exclusive - Heat related issues are said to be at the root of Apple's latest iMac blunder, which has left the computer maker without a consumer desktop offering for the busy back-to-school shopping season.

Earlier this month, Apple's Public Relations department performed a most unorthodox act when it quietly announced to the Mac faithful that the company had run out of its current iMac G4 computers and new models would not be available for another two months.

"We planned to have our next-generation iMac ready by the time the inventory of current iMacs runs out in the next few weeks, but our planning was obviously less than perfect," read a statement published exclusively on the company's online store, but not reflected in an official press release.

Apple later delivered the same statement to analysts via e-mail, but would not comment further on the issue, leaving both consumers and analysts in the dark.

Reliable information suggests that Apple had initially intended to launch an all-new iMac product-line early this Summer, which sources confirmed would include a low-end PowerPC G5 processor and a completely remodeled appearance.

What exactly caused the unfortunate iMac delay, Apple may never say. However, well placed sources tell AppleInsider that a heat issue affecting the new iMac enclosure is to blame.

Reportedly, the the newly designed iMac enclosure faced repeated cooling issues due to the way Apple designed the internals of the new iMac. "Apple's industrial design of the new iMac attempts to cross new boundaries, but physics is obviously not on on their side," said one reliable source, who claims that at one point Apple believed that it had fixed the cooling problems, but were later disappointed.

Meanwhile, sources privy to pre-production details of the iMac G5 have reaffirmed previously published reports, describing the iMac similar to Apple's newly announced Cinema displays.

"[The iMac G5] is totally different from the current iMacs and looks very simple from outside," says one source who claims to have had first-hand contact with the computer. "It's just a box with a support, but inside is complex."

The overall footprint of the new iMac is said to be very compact, aided by a logic-board that is mounted behind the computer's LCD screen. A purported manufacturing sketch of a pre-production iMac obtained by AppleInsider in June shows a thick display module which hovers above the desk from a single support. A vertically mounted, slot-loading optical disk drive from Matsushita-Kotobuki Electronics is depicted on the upper right side of the unit.

Prior to the recent shortcomings, the development of the iMac G5 was said to be a tedious process involving constant alterations at the request of a "certain someone."

Sources close to Apple manufacturing report that the company will begin mass production of the new iMac in the next few weeks, most likely accumulating sufficient quantities of the computers before they are unveiled to the public.

Analysts now expect Apple to officially announce the new iMac during Apple Expo, which takes place in late August.

Already, one overseas Apple reseller has posted a note on its website, claiming that stock of the new iMacs is due to arrive the week of September 5th.