No right to open file once copied on the desktop I'm new to Mac, so I may not have the correct vocabulary.


We have a Mac 10.5.x configured to share files with AFP and SMB.  
We have 4 other Mac as clients, various versions between 10.5 and 10.6.
Each of them access the server with the correct user+password.  
The share is now configured to ignore permissions, but the problem was identical before that.  
We can create/open/modify/delete/rename/etc files on the server, from every clients.  


The problem :
When we copy a file from the server to the desktop of a client, the copied file can not be opened. The error message says the permissions don't allow the file to be read.
This is for every file from the server, on all 4 clients.
The files are copied with the finder, from the client.

Edit:
I checked the permissions. 
On the server's share, when I look at the permissions from a client computer, every files are -------rw- cedric cedric (read-write for everyone) with the user and group identical to the people connected (here cedric, but this is another user when viewed from another computer).
Once the file is copied on the desktop, the permissions and owner are the same. So it is not possible to open the file because the permissions are not correct (I just tested on Linux, when a file is RW for everyone only, the owner can't open it).

So, is there a way to automatically copy the files with better permissions ? Or the share the files correctly ?

Edit:
Every client computer is now upgraded to 10.6.x for the oldest, and 10.7.x for the two others. The problem is exactly the same.
I also noted one computer can't save files from Adobe softwares to the server. The user saves the files on his desktop, then use the finder to move them to the server.
There are known issues (Apple-created bugs) with several revisions of OS X 10.5 Leopard Client and AFP file access, including permission problems and in certain cases even the potential to lose or overwrite files completely.

There is no work-around for these bugs, they are in the operating system itself and can be reproduced on 2 freshly-formatted &amp; installed Macs running Leopard 10.5, and most or all of the later revisions, i.e. 10.5.1, 10.5.2, etc.

Your best solution is to be sure to update all 10.5 Macs to 10.6.8 Snow Leopard. Failing that, updating everything to 10.5.8 (the last release of Leopard) may solve your problems.

Here's a list of references that go into more detail:

http://support.grouplogic.com/?p=1508

https://discussions.apple.com/thread/1423847

http://www.insanelymac.com/forum/topic/67625-preping-for-105-permissions-issues-with-afp-shares/

http://lists.apple.com/archives/macos-x-server/2010/Dec/msg00267.html

http://www.mailinglistarchive.com/html/xsan-users@lists.apple.com/2008-07/msg00409.html