Ever since upgrading to Mac OS X 10.6.3 I had been unable to copy files from my MacBook to a Linux Samba share, which had previously worked flawlessly. The file copy would fail and Finder displayed the error message: “The operation can’t be completed because you don’t have permission to access some of the items” or “The Finder can’t complete the operation because some data in xxx can’t be read or written. (Error code -36)”.I found several articles suggesting solutions, the only one that eventually worked for me was to add the line “unix extensions = no” to the [global] settings of the smb.conf file on the Linux server. After a restart of the SMB processes file copying is working again.

Thanks for all the time I wasted on resolving this one Apple!