Go 940 - Device not connected?????

Hi All

I've just purchased a Go 940. I connected it to my laptop to update the unit (navcore is 842337)in Tomtom home before updating the maps. The problem I have is when I connect to the laptop its not recognized. The unit doesn't show up in 'My Computer', or Tomtom home.

I have previously (4 weeks ago) used this same laptop to successfully update a Go 930.

I've tried the unit with all USB connections, the USB ports work with other devices like mobile phone and memory stick etc.

I am using the latest Tomtom home, which shows 'NO DEVICE CONNECTED'.

I have also tried using the car mount with the mini usb data cable from the 930 to no avail, instead of the supplied desktop cradle.

The device charges fine when on the desktop cradle or the 930 cable and windscreen holder.

So, any ideas?????

If the unit connector is knackered, is there another way around this, like putting it on a micro sd card?

Thanks