Sony are looking even redder in the face than some of their unfortunate consumers after recalling nearly 500,000 Vaio laptops today, because the machines had developed the slightly unhelpful fault of catching fire. 

What's more, they allegedly knew about it already - a source who wished to remain anonymous told the Guardian that the problem had been flagged last August.

"We fully recognise that there were problems with the speed of our response, but we are doing our best to address the problem and make sure it doesn't happen again," said the mystery person.

Sony have insisted the issue will not affect their earnings, but some analysts believe that the brand could suffer because of it.

"If these things pile up and reveal that Sony's structurally weak, then its brand value will definitely be hurt," Mitushige Akino, of Ichiyoshi Investment Management, told Reuters.

The problem affects Vaios produced between May 2007 and July this year. Faulty wiring near the machine's hinge has the potential to short-circuit and overheat. Sony claimed to be aware of 203 cases - most in Japan, where 83 faulty machines have been identified. Reports say that a small number of users received minor burns.

Sony have pledged free repairs for the 48 countries where the potentially broken model is on sale, including the US and UK.

Shares in the company have already fallen - briefly to ¥3,850, their lowest since 2005, but they're currently holding at ¥3,880, a drop of 4.2%.