After searching for a solution to this problem for ages I finally came across the answer on the Oceanside Coding website.I used Lingon, see downloads page for link, to install the plist file as it saves messing about with permissions in Terminal. Just use Lingon to create a new Users Daemon file, switch to Expert mode and replace any text with the following code:

Click Save and enter your Admin password. The plist file will now be installed.To enable this to work just log out and back in and you should find that SMB file sharing is now working.

Tags: Apple, MacOSX, SMB