diff --git a/jobmanager/clients.py b/jobmanager/clients.py
index a2a298b..38de94b 100644
--- a/jobmanager/clients.py
+++ b/jobmanager/clients.py
@@ -67,7 +67,11 @@ def merge_arg_and_const_arg(arg, const_arg):
     kwargs.update(arg)
     # remove args as they have been constructed explicitly
     if 'args' in kwargs:
-        kwargs.pop('args')
+        del kwargs['args']
+        
+    # remove id, when it comes from the persistentDataServer 
+    if 'id' in kwargs:
+        del kwargs['id']
     
     return args_dgl, kwargs
 
diff --git a/jobmanager/servers.py b/jobmanager/servers.py
index 2a65133..a9a8284 100644
--- a/jobmanager/servers.py
+++ b/jobmanager/servers.py
@@ -85,10 +85,10 @@ class PersistentData_Server(JobManager_Server):
                 print("{}: overwriting existing data is DISABLED".format(self._identifier))
          
     def process_new_result(self, arg, result):
-        self.pds[data_as_binary_key(arg)] = result
+        self.pds[data_as_binary_key(arg.id)] = (arg, result)
         
     def put_arg(self, a):
-        a_bin = data_as_binary_key(a)
+        a_bin = data_as_binary_key(a.id)
         if self.overwrite or (not a_bin in self.pds):
             JobManager_Server.put_arg(self, a)
             return True