Now that I had to read about the licenses for the Windows Server and the Terminal Sever, I understood many of the network problems we have faced with windows shares and printers in Windows XP PCs:
-Windows XP Home: Allows only 5 users to connect.
-Windows XP Professional: Allows only 10 users to connect.
Of course there are no technical reasons for that, is just a matter of marketing in order to force users to buy more expensive Windows Versions.
So, my recommendation, If you need to have a Windows share, Use Linux, Make a SAMBA partition for your windows users, and you have no users quantity limits, only hardware limitations, of course.