Hi I have, what I think, is a weird one. I am running 2008 r2 for the DFS and accessing with Windows 7 systems.
We have a DFS share that all files are PDF's, when opening all users with access (myself included) get different errors when opening the PDF's. For example error 108, 119, out of memory etc. I would have said this was an issue with adobe reader or the files themselves, but when I can copy the file to my desktop it opens fine. Previous versions of the files open fine as well including ones from when the issue was first reported.
Now here is where I am getting a little confused: If I copy the file to my desktop, then make a copy back to the DFS folder and select 'copy, but keep both files' that copy won't open, or will only open once before it starts to error out again. If I delete the most recently copied version ie. file(2), from the DFS share then all the pdf's work without error until I reboot the system.
All other DFS shares work without error and this one is, as far as I can tell setup the same way.
Quick note, all the files in the sub-folders open without error, including PDFs. Also there are only PDFs in that location, so I have not tried with other file types though that is my next step and I will update once I have done that.