Hi Lee,
Quick update....
Yes, had been 'full formatting' it rather than quick formatting it, but have tried both, as well as the MiniTool Partition software.
Replaced the card today with a new one (still 8GB Verbatim). Still the same error, so wondering if I have something else going on now such as a fault on the Pi or bridge. USing both a ANKER battery and a 5V Pi power pack to see if ther's anything else messing me around. Have also tried booting without the WiFi dongle, Antenna and GPS dongle. Will download the PA software again, just on the off chance something has corrupted during the unzipping.
Harry