Kay - I've tried reinstalling the game a few times. I have now also deregisterd first and thought I would try installing it again - but I have now had enough! - I may try again in the future! I am a bit disappointed but Acalius dropped through the letter box this morning
and I have several recent games as well as a backlog of older ones that I haven't got round to playing yet! (Hopefully none of them will be as much trouble!)
Thanks everyone for your help!