Well stone the crows, blow me down with a feather and all that stuff! After a really stubborn week where I couldn't get the blimmin' camera to do anything it has decided to come back to life and looks like it's fully charged!
So far I've reset it using the pin hole reset button, re-flashed the unit using the instructions on the Drift website and tried re-charging it using three different chargers. I kind of gave up and just left it plugged in to the USB port on the PC - a trickle charge over four days or more seems to have done the trick.
Shame I couldn't get it going in time for my trip to the Brecons last weekend!
Any thoughts or advice on the best charger to use?