Default intermittant car charger fault

Please help anyone,

I have tried a number of different car chargers including the SE AN 300 which apparently is the recommended one, and of those that actually worked they all have a problem.

Sometimes they charge fine but often the phone will stop accepting a charge even though the charger is lit up and apperently working. Un plugging and re plugging in the charger will fix things for a while but then it stops again.

The handset charges fine from mains and pc usb, its just from the car I have problems.

Any ideas? This is really getting me down now as I work away from home a lot I really need reliable on the road charging.

T I A :)