Even after following this article my 6th gen iPod nano still cannot be identified, why?

I have just had my iPod Nano 1st generation replaced by an iPod Nano 6th generation due to a recall because of a battery issue but the new iPod, whilst detected, cannot be identified by iTunes even after reinstalling iTues. Why and what do I need to do to resolve the issue? My 1st generation iPod was fully recognised.