TomTom has issued a software update to fix a GPS signal destroying issue called the 'leap-year' bug.

The fix has been necessary after firmware problem caused its SatNavs to lose GPS signal and present a grey screen. TomTom said limited model have been affected and only a temporary fix was available by switching the device on and off.

TomTom said: "Some customers have been experiencing GPS positioning issues since 31st March. The issue is caused by a ‘leap year’ bug in the software of the GPS receiver provided by a third party. A software update fixing the issue is now available via MyTomTom."

Customers can download and update their SatNav device by plugging it into a PC and using the MyTomTom software.

The problem, which lasted a few days occurred on a global scale with customers from the UK, Italy, the US and Australia amongst those posting on TomTom's forum about the problem.

One user said: "My Tomtom Live 1005 stopped picking up gps on Sunday 1 April. It stuttered a cpl of times throughout today ( Monday 2 ), enough to get a brief location of where I was, but only for a cpl of seconds. Still no gps signal. Have even resorted to factory reset but this hasnt fixed the problem."