Nailed it I hope.
Due to an incomplete upgrade the values in the config table had been updated to reflect the new version, this was then stopping the rest of the tables being upgraded.
Not sure how I managed to do this, probably got confused swapping databases and directories?
Once I replaced these values with the correct numbers from the old version.php the rest worked. Guess it was just as well I have followed your back up suggestions.
Thanks for this fantastic piece of software.
Tom