While I know that this will not be the solution to everyone who is having problems between Snow Leopard and various CIFS (SMB) server implementations, I wanted to post my solution with as many keywords that google would pick it up and hopefully help a few other people.
The Symptoms: After upgrading my new Mac Mini to Snow Leopard a few weeks back, I started noticing some strange behaviors with applications that had to deal with my NAS (which is an OpenSolaris box with ZFS shares). I did not immediately make the connection to my NAS, all I saw was problems in apps. The first problem was with iTunes which stores all of its library on a NAS volume. iTunes stopped downloading Podcasts. This was not high priority to me, but two days ago, I went to purchase the 13th episode of Dollhouse, Epitaph One, and it would not download, giving an error -48.
My investigations: I checked the network connections and packets were getting out. I finally tried switching the library location back to the local hard drive and that fixed it, so I knew that there was something wrong with the storage on the NAS. However, when I tried to copy files to the NAS via the command line, everything worked fine, which stumped me for a while. I finally tried copying something from the Finder, and it also failed, this time with the error “The Finder could not complete the operation because some data in “” could not be read or written. Error code -36)”
AHA! It appears there is a problem with Cocoa apps communicating to the NAS. I looked in the system logs and started seeing the following error:
smb_maperr32: no direct map for 32 bit server error (0xc00000e5).
My Solution: Google brought up many people with this issue, but nothing that looked like a good solution. Here is where I would love to say that I had a brilliant flash of wisdom that solved the problem, but if that occurred, it was subconscious. Being stumped, I put the problem aside.
Yesterday, as I was putzing around the house, I got the idea to upgrade the OS of my OpenSolaris box from 2008.11 to 2009.06. To be clear, I in no way did this as a potential solution to my iTunes problem. I found a great set of instructions from Michael Sullivan on his Frame Dragging blog: A Smooth Upgrade - OpenSolaris 2009.06 snv_111b. Given how painful almost everything is with Solaris, I was impressed how smoothly this went (especially in light of my current procrastination of upgrading my Fedora 9 box).
After the upgrade, I thought, what the hell, let me see if this made any difference to my former problem. I dragged a file in the Finder to one of my NAS volumes, and bang! it copied. So, apparently there is some slight difference between the CIFS server in the 2008.11 version of OpenSolaris and the 2009.06 version that makes Snow Leopard happier. I don’t think the problem was with OpenSolaris, my feeling is that Snow Leopard just isn’t handling an odd situation right, the new version of OpenSolaris just happens to work more like Snow Leopard likes.
So, I hope this helps someone other than me.