OK....ive just run year end for end of march this year and realised I didnt set the current program date to 31 March 10 as I should have. Is this a problem?
When doing a year end you should have the date set to the last day in that financial year. As Sue says if you did a back up prior to running year end (which is recommended by Sage) then you can restore and do it again.
The other thing is why have you done the year end? Has your accountant advised you to do so? Usually, when I am working with accountants I do not complete the year end on Sage until after I have passed a backup of the program to them, they have done their adjustments and then given me the the opening balances for the next year.