diff --git a/__init__.py b/__init__.py
index b7d2074..cf3212d 100644
--- a/__init__.py
+++ b/__init__.py
@@ -63,8 +63,8 @@ def run(group, arglist):
            return
         action = arglist.pop(0) if hasattr(serv, 'do_' + arglist[0]) else 'gui'
         instance = arglist.pop(0) if arglist[0] and arglist[0] not in serv.services else None
-        if instance is None and len(serv.info) == 1:
-            instance = list(serv.info)[0]
+        if instance is None and serv.main_ins:
+            instance = serv.main_ins
         if instance is not None:
             arglist.insert(0, instance)
         arglist.pop()  # remove dummy argument
diff --git a/base.py b/base.py
index 00f023a..fd2e399 100644
--- a/base.py
+++ b/base.py
@@ -83,7 +83,7 @@ class ServiceManager:
     pkg = ''
     revcmd = {}
     USAGE = None
-    main_instrument = basename(expanduser('~'))
+    main_ins = basename(expanduser('~'))
 
     def __init__(self):
         self.env = {}
@@ -137,7 +137,7 @@ class ServiceManager:
         for ins in parser.sections():
             section = dict(parser[ins])
             if ins == 'MAIN':
-                ins = self.main_instrument
+                ins = self.main_ins
             command = section.get('%s_command' % self.group)
             self.revcmd[command] = self.group
             nr = section.get(self.group)
@@ -193,7 +193,7 @@ class ServiceManager:
                     match = cmdpat.match(cmd)
                     if match:
                         gdict = match.groupdict()
-                        ins = gdict.get('ins', self.main_instrument)
+                        ins = gdict.get('ins', self.main_ins)
                         serv = gdict.get('serv', '')
                         if cfginfo is not None and 'cfg' in gdict:
                             cfginfo[ins, serv] = gdict['cfg']
@@ -204,8 +204,10 @@ class ServiceManager:
         self.get_info()
         if ins not in self.info:
             raise KeyError("don't know %r" % ins)
+        sp_ins = ' ' + ins if ins != self.main_ins else ''
         if not self.get_procs().get(ins, {}).get(service):
-            raise ServiceDown('%s %s is not running' % (service, ins))
+            startcmd = '%s start%s' % (self.group, sp_ins)
+            raise ServiceDown('%s%s is not running - please use %r' % (self.group, sp_ins, startcmd))
 
     def stop(self, ins, service=None):
         """stop service (or all services) of instance <ins>"""
diff --git a/seaman.py b/seaman.py
index c42271f..e8c5e2a 100644
--- a/seaman.py
+++ b/seaman.py
@@ -78,6 +78,7 @@ class SeaManager(ServiceManager):
         except ServiceDown as e:
             self.usage()
             print(str(e))
+            return
         except KeyError:  # running on an other machine?
             self.usage()
         run_command('SeaClient %s' % ins)