Guys, I've been astonished by the help I've received with this problem - thank you very much everyone. I'm afraid to say that the problem was as stupid as me consuming the exception on a particular record. Best practice point to self, and I'm really sorry for wasting peoples time on such a simple thing. I normally go out of my way to Google for problems, but since 726301 is not a magic number/ceiling (as it was just an exception) I was really scratching my head over this one without seeing the obvious. Anyway, thanks again for everyone's time, and for the suggestions. Ben