I don't really know what I did to cause the problem, but whatever it was I didn't intend to do it. I no longer have letters up for the column headers, this makes it a real pain to type in forumlas.

Anyway, attached is a screenie of what I'm talking about, anyone know how to make it normal again?
http://www.umr.edu/~ddavison/excel.jpg

In Excel, click Tools/Options
Select the "General" tab and UNtick the "R1C1 Reference Style" checkbox.

Ah, many thanks RBS.