i have tried all kind of shares defined for this path (afp, smb, nfs)
only shh as root works (what a surprise :-) )
after restarting the amuled everythings works normal, so there is no permission problem.
I know, it sounds a bit strange - thats the reason i asked for help :-)
By now i trie to fix it with a little shellscript activated by the ExecOnCompletionCommand option.