I work with both Win 2000 server and Mac OS X server this puts me in a good position to judge(MD loves Mac's). Though we only use Windows as a database host and some FTP action. Macs are used for the webservers and FTP servers that are more critical as they last longer with out human...
After moving from ASIP 6.3 to X server the ability for PC to connect to the MAC server seems to have gone. They see the server in the domain but don't accept the password as a valid one. Yes it is the right password:)