Great I have fixed it, I discovered that in the Departments screen there is a box called 'Price tag', now, I thought that was where i put the £-currency sign, Dohhh!!!
However, Having solved that, it brings up another problem, trying to change it back ! I have set up another Trigger,Rule, Action to revert to Normal price list but it wont change back, is it because the original prices do not have a "tag"? How do you give the Original price list a 'tag' ? or is there some other way to do it?