TomTom Go powering off

I have in the last month updated my tom tom go to the november update. I did a backup and all seemed fine while running the update. On the recent occasions i have used the tomtom it has powered off and lost my destintation. This doesnt happen when its has the cigerette charger plugged in, but it does have a full battery charge.

I would try the old version but i have since lost my hard drive!! Dohh.. so wondered if anybody else had this problem with the new update or is it a fault that the update hasnt caused.

If anybody has any recommendations i would be gratefull

With thanks

Sarah