back alley - Thanks but I'm not shooting rapidly. I always let it write to the card fully before shooting another shot e.g. watch the red blinking light.
paradox box - Thanks for the help. As above I'm not shooting quickly at all - I shoot once and let it write. I go fairly slowly with my shooting style.
I didn't try different batteries that I already had as I knew the six or so I was given in the sale would be fairly old so I went out and spent $40 on a good one at a local battery store (avoiding the $6 ebay ones), allowed it to charge fully but same thing unfortunately.
That doesn't discount the probability that an Epson battery may fix the issue as Rich Cutler has mentioned but I am fairly sure if it was a battery issue, this one would have solved it. I can get an Epson from Japan for about $70 but I'm not sure that is going to fix anything.
kdemas - I haven't tried that for as long as overnight so will give that a go - thanks very much.
Thanks again to everyone for their help. It feels so helpless having a big black dead brick instead of my beautiful camera!