I had the same problem that you guys had described above and also fixed it with apt-get smbfs. Now, my files on a samba/smb share (Buffalo Terastation: newbielink:http://www.buffalotech.com/products/product-detail.php?productid=97 [nonactive]) are seen by the MDs and orbiters, but they do not play. If I copy them over to the core, they play fine. I thought this may have been a permissions issue, but after looking into that, it's not. The files are easily accessible by my regular (linux) desktop using smbclient without any permission issues.
I'm using a secure(r) method by mounting with smb credentials in /etc/fstab, but I suspect this is the problem. Does pluto use a different fstab file?
Thanks to any help you can provide!