Slow transfer Macintosh to Win2K Server

I have just installed a Windows 2000 Server. It is mainly to be used for Macintosh file storage.

The main spec is P2-350 / 256mb / 120GB 10/100mbs network.

File Copy form the server is good but file copy from any MAC to the server is 8 to 10 times slower. It works fine from any PC.

Any ideas ?