It is possible the problem is Acrobat Reader not working with network home directories. It is a long time since I looked in to this but I think around about Acrobat Reader 9 Adobe broke the ability to use Reader with network home directories. This bug was originally introduced with Acrobat Pro 7 (but not Reader), fixed in Acrobat Pro 8.1, reintroduced in Acrobat Pro 9 (and Reader 9) and may still exist.
See http://www.macsmarts.com/acrobat-reader-crashes-with-network-home-folder-account s-on-os-x/
The fix for Acrobat Pro and apparently also Acrobat Reader is to redirect a folder to a location on your local harddisk instead of the (in this case) normal location in your network home directory on the server. See the above article.
Note: With Snow Leopard Server you can automate this redirection.
Unfortunately Adobe are completely brain dead regarding ensuring their applications work properly with network home directories. Their attitude is that they do not support using their software with servers (literally that is what they said).
These days Preview at least in Lion and later is able to do almost anything your average user needs with PDFs including deleting or adding pages, adding notes, even producing password protected PDFs.
PS. Even Microsoft who are notorious for their poor Mac programming do a better job than Adobe with regards to working with network home directories.