No problem, went that route checking fuses, wires and the lot before I asked for help.
I went through the reset process, drove the bike around the neighborhood and voila, the gas gauge started working again.
Apparently if you unhook the battery it affects the fuel gauge, but thanks to help here we got rid of that gremlin and it is working fine now.
I realise that this may sound stupid and perhaps insulting. Have you checked the fuses. I had this trouble and it turned out to be a small fuse under the seat. Evidently there is a link between the power to the fuel guage and other stuff and I had blown a fuse without realising it.
