Snow Leopard slow FTP login

How do I improve login times on the Snow Leopard FTP server so that it can match Microsofts IIS timings?

Today it seems to take up to 2 minutes before I get the directory listings to appear in the client side,

If I use a IIS server next to this machine that one do the same job in just 5-10 seconds!

They both share the same Router and are configured for Passive Mode operations.