diff --git a/secop_psi/sea.py b/secop_psi/sea.py
index 749207c..d16bfad 100644
--- a/secop_psi/sea.py
+++ b/secop_psi/sea.py
@@ -121,7 +121,7 @@ class SeaClient(ProxyClient, Module):
             if port is None:
                 raise ConfigError('missing sea port for %s' % instance)
             opts['uri'] = 'tcp://localhost:%s' % port
-        self.objects = []
+        self.objects = set()
         self.shutdown = False
         self.path2param = {}
         self._write_lock = threading.Lock()
@@ -134,8 +134,9 @@ class SeaClient(ProxyClient, Module):
         Module.__init__(self, name, log, opts, srv)
 
     def register_obj(self, module, obj):
-        self.objects.append(obj)
-        self.path2param.update(module.path2param)
+        self.objects.add(obj)
+        for k, v in module.path2param.items():
+           self.path2param.setdefault(k, []).extend(v)
         self.register_callback(module.name, module.updateEvent)
 
     def startModule(self, start_events):
@@ -272,9 +273,8 @@ class SeaClient(ProxyClient, Module):
                         readerror = HardwareError(value)
                     path = path.rsplit('.', 1)[0]
                     value = None
-                try:
-                    module, param = self.path2param[path]
-                except KeyError:
+                mplist = self.path2param.get(path)
+                if mplist is None:
                     if path.startswith('/device'):
                         if path == '/device/changetime':
                             result = self.request('check_config %s %s' % (self.service, self.config))
@@ -284,15 +284,14 @@ class SeaClient(ProxyClient, Module):
                                 self.DISPATCHER.shutdown()
                         elif path.startswith('/device/frappy_%s' % self.service) and value == '':
                             self.DISPATCHER.shutdown()
-                    # print('UNUSED', msg)
-                    continue  # unused parameter
-                oldv, oldt, oldr = self.cache.get((module, param), [None, None, None])
-                if value is None:
-                    value = oldv
-                if value != oldv or str(readerror) != str(oldr) or abs(now - oldt) > 60:
-                    # do not update unchanged values within 60 sec
-                    self.updateValue(module, param, value, now, readerror)
-
+                else:
+                    for module, param in mplist:
+                        oldv, oldt, oldr = self.cache.get((module, param), [None, None, None])
+                        if value is None:
+                            value = oldv
+                        if value != oldv or str(readerror) != str(oldr) or abs(now - oldt) > 60:
+                            # do not update unchanged values within 60 sec
+                            self.updateValue(module, param, value, now, readerror)
 
     @Command(StringType(), result=StringType())
     def communicate(self, command):
@@ -453,8 +452,8 @@ class SeaModule(Module):
                     include = True
                     for paramdesc in descr['params']:
                         path = paramdesc['path']
-                        if path.endswith('is_running'):
-                            # take this always
+                        if path.endswith('is_running') and issubclass(cls, Drivable):
+                            # take this independent of visibility
                             is_running = paramdesc
                             continue
                         if paramdesc.get('visibility', 1) > visibility_level:
@@ -550,7 +549,7 @@ class SeaModule(Module):
             if key in extra_module_set:
                 extra_modules[name + '.' + key] = sea_object, base, paramdesc
                 continue  # skip this parameter
-            path2param[hdbpath] = (name, key)
+            path2param.setdefault(hdbpath, []).append((name, key))
             attributes[key] = pobj
             # if hasattr(cls, 'read_' + key):
             #     print('override %s.read_%s' % (cls.__name__, key))