Sony's demo PlayStation 3 consoles on display at last month's Tokyo Games Show were plagued by numerous reset-requiring crashes, it has been alleged. The claim has prompted fears the machine may not be ready for prime-time when it ships into the US and Japan later this year.

The allegation was made Macquarie Equities analyst David Gibson in a note to investors, according to a Washington Post report. Gibson himself admitted the cause of the problem was unknown - he suspects heat issues caused by the sealed cases in which each PS3 was placed to prevent anyone taking a peek inside the console, and the high temperatures experienced at the venue itself.

That's entirely possible, particularly since the PS3 is expected to contain some serious cooling technology. Even Microsoft's Xbox 360 needs a liquid cooling system to prevent the console from overheating, as revealed by a recent attempt to convert the console into a laptop.

Confirmation, of sorts, comes via PS3M magazine in the UK, recently given a demo of the machine. Staffers claim the console is not only very quiet but also very heavy, factors which point to some aggressive, fan-less cooling - not to mention a hefty in-box power transformer.

Unlike the Tokyo demo units, the PS3M machine wasn't sealed in, allowing plenty of space for the heat to escape. Of course, none of these consoles may be consumer-ready equipment, even though Sony is now believed to be punching out PS3s as fast as it can.

The Tokyo Game Show problems certainly worried Gibson, and they appear to have scared investors too, knocking ¥130 ($1.22) off Sony's share price yesterday, the day after Gibson's report was sent out. ®