I'm sorry if this has been covered, I haven't had time to read this maillist much this year! Just want to get this solution googled for some poor person having the same problem.
If you are experiencing this problem the solution is use sendfile=no In your smb.conf -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html