samba - Sep 2008 - XP Client sees two files with same name.

Hello.
I'm running 3.0.32 on FreeBSD 6.3/i386 sharing some folders to Windows 
clients.
 From an XP client I sees a particular file two times in the same folder 
(same identical name, same size, same dates, ecc...); I double-checked 
on the server and from there I only see it once.
Where should I start looking into this?
Could this be a samba problem? Or rather a Windows one?

  bye & Thanks
	av.