Permissions Problem on AFP-reshared NFS mount

(Apologies in advance for cross-posting this here and on macosxhints.com)

I’ve got quite a peculiar problem on my Leopard Server running 10.5.2:
The server has an NFS exported share mounted under nfs_reshared. The NFS server is a Linux box running OpenSuse 10.3 (which shouldn’t matter, as I’m quite certain that the whole NFS server side is allright). I’m resharing this NFS share on the Leopard Server with AFP.
So, in short my setup looks like this:
LINUX BOX /export -> NFS -> Leopard Server /nfs_reshared -> AFP -> Leopard Clients
When my users try to copy files to the mounted directory, the first file gets copied, then the copy stops with a “permission denied” message. I’ve tracked the problem down to this:
– While first file gets written, then the Finder tries to create the .DS_Store file.
– The user gets a “permission denied” message, but the .DS_Store file gets created nonetheless. The copied file gets created as well, but it’s zero bytes long.
– Trying to manipulate the .DS_Store file (using the shell) works, but using the Finder to copy files still isn’t possible.
– After a short while, the .DS_Store file gets automatically deleted for some reason.

On a client machine, a shell transcript looks like this:

Client-Mac:test kiezpro$ pwd
/Volumes/Leopard-Server/test
Client-Mac:test kiezpro$ ls -al
total 0
drwxrwxrwx  2 kiezpro  kiezpro  264 Apr  5 14:43 ./
drwx------  7 kiezpro  kiezpro  264 Apr  5 14:20 ../
Client-Mac:test kiezpro$ touch .DS_Store
touch: .DS_Store: Permission denied
Client-Mac:test kiezpro$ ls -al
total 8
drwxrwxrwx  2 kiezpro  kiezpro  264 Apr  5 14:43 ./
drwx------  7 kiezpro  kiezpro  264 Apr  5 14:20 ../
-rw-r--r--  1 kiezpro  kiezpro    0 Jul  9  2037 .DS_Store
Client-Mac:test kiezpro$ sync
Client-Mac:test kiezpro$ ls -al
total 8
drwxrwxrwx  2 kiezpro  kiezpro  264 Apr  5 14:43 ./
drwx------  7 kiezpro  kiezpro  264 Apr  5 14:20 ../
-rw-r--r--  1 kiezpro  kiezpro    0 Jul  9  2037 .DS_Store
Client-Mac:test kiezpro$ 

Note the maxed-out date on the .DS_Store file.

On the Server, it works fine:

Client-Mac:~ kiezpro$ ssh leopard-server
bash-3.2$ cd /nfs_reshares/export/test/
bash-3.2$ ls -altr
total 16
drwxrwx---  6 admin        wheel           4096 Apr  5 14:20 ..
drwxrwxrwx  2 kiezpro      members         4096 Apr  5 14:46 .
bash-3.2$ touch .DS_Store
bash-3.2$ ls -al
total 16
drwxrwxrwx  2 kiezpro      members         4096 Apr  5 14:50 .
drwxrwx---  6 admin        wheel           4096 Apr  5 14:20 ..
-rw-r--r--  1 kiezpro      members            0 Apr  5 14:50 .DS_Store
bash-3.2$ 

So the permissions on the NFS server are apparently OK, otherwise I wouldn’t be able to touch the file from the Leopard Server. Interestingly, this time the .DS_Store file doesn’t get deleted.
On the NFS server, /etc/exports looks like this:

/export 10.10.10.2(rw,insecure,async,no_subtree_check,no_root_squash)

As mentioned above, I’m pretty certain that the NFS server is configured correctly.
I don’t know what’s causing the problem here, has anyone had similar problems and solved them?