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 aPC 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."