Running a Windows guest on a Linux Host and using Samba to share files from the host, I have witnessed extremely slow file transfer performance. I have seen this on multiple stations and multiple situations.
http://www.vmware.com/community/thread.jspa?messageID=509389
Basically:
ethtool -K eth0 tso off
and restart Samba. This worked for me, and I also put the line in the Samba start script.
Also suggested:
ethtool -K eth0 tx off
ethtool -K eth0 sg off
