Thank you, both, for posting this; I learnt something (totally irrelevant but worth learning) as a result:
I don't often copy a complete worksheet within a workbook, but you made me wonder what would happen if I did so, and the sheet I was copying had a named range on it. There would then be two named ranges, one on each copy of the worksheet, and both with the same name?
No, no error, and Yes, two named ranges with the same name, but referring to different ranges. Scarily misleading. In Excel2003, incredibly misleading, because there isn't really a useful tool to see what's going on. In Excel2007, the name-manager explains that named ranges have scope, and that the scope of the original range is global, but the scope of the copy of the range is limited to its own worksheet. Presumably it takes priority over the global version on its own sheet.
Yup, I can see the logic, but before combining named ranges with copying worksheets, that's a piece of information worth knowing.