We have a Synology Diskstation RS409 and I have named it fileserver. On all my XP and Vista computers I can map it by \\fileserver but when I try to do that on a Win 7 computer I am asked for network credentials and even the domain admin login doesn't work. I can only access it by using the IP address of the NAS. I recently updated the firmware to the latest version too. It doens't seem like a DNS issue but I am not sure.