Emmitt, Thanks for your replies. I have explained in my reply to Mike what I was doing, however I wasn't trying to 'manipulate' the values in the computed column, they were just the link. Anyway, what I was doing is no longer permissible, so I am in for a rethink on how to do this.
At least I now know where the error comes from. Thanks for the info on the access violation error - I will check that out, however being a new machine I think that I have only applied the one update so far. Regards, John Docherty
