Thank god for that, I found it, I had a feeling I'd read something about this before.
Took my bike out for the first time in quite a while, what with the new baby and all, got my mot done, taxed it and then nipped in to the office in the evening to get something and decided to take the opportunity to take the long way home.
So there I am revelling in the fun of blasting the SD down some country lanes and suddenly I see my speedo jumping randomly with anything up to 180mph, which although I was going quite well considering I haven't been out much I thought that was a tad optimistic , followed by the FI light coming on for a few seconds before going off again, this was repeated the rest of the way home.
Typical I thought, my bloody warranty ran out just 3 weeks ago, if only I'd taken the bike out earlier.
Still, hopefully based on this thread it's easily fixed, I was thinking whether battery connections might be an issue but hadn't had a chance to check yet, here's hoping.