diff --git a/src/CommNetConstellation/CommNetLayer/CNCCommNetScenario.cs b/src/CommNetConstellation/CommNetLayer/CNCCommNetScenario.cs
index b13e637..a290e48 100644
--- a/src/CommNetConstellation/CommNetLayer/CNCCommNetScenario.cs
+++ b/src/CommNetConstellation/CommNetLayer/CNCCommNetScenario.cs
@@ -324,7 +324,7 @@ private void cacheCommNetVessels()
             List<Vessel> allVessels = FlightGlobals.fetch.vessels;
             for (int i = 0; i < allVessels.Count; i++)
             {
-                if (allVessels[i].connection != null && allVessels[i].vesselType != VesselType.Unknown)// && allVessels[i].vesselType != VesselType.Debris) // debris could be spent stage with functional probes and antennas
+                if (allVessels[i].connection != null && allVessels[i].connection.ControlState != VesselControlState.None && allVessels[i].vesselType != VesselType.Unknown)// && allVessels[i].vesselType != VesselType.Debris) // debris could be spent stage with functional probes and antennas
                 {
                     CNCLog.Debug("Caching CommNetVessel '{0}'", allVessels[i].vesselName);
                     this.commVessels.Add(allVessels[i].connection as CNCCommNetVessel);
diff --git a/src/CommNetConstellation/CommNetLayer/CNCCommNetVessel.cs b/src/CommNetConstellation/CommNetLayer/CNCCommNetVessel.cs
index a881d99..7d6c4db 100644
--- a/src/CommNetConstellation/CommNetLayer/CNCCommNetVessel.cs
+++ b/src/CommNetConstellation/CommNetLayer/CNCCommNetVessel.cs
@@ -97,9 +97,9 @@ protected override void OnNetworkInitialized()
             {
                 validateAndUpgrade(this.Vessel);
 
-                if(readCommandData().Count <= 0) //no probe core/command module to "process" signal
+                if (readCommandData().Count <= 0) //no probe core/command module to "process" signal
                 {
-                    this.vessel.connection = null;
+                    this.controlState = VesselControlState.None;
                     throw new Exception();
                 }
 
@@ -155,10 +155,17 @@ private void vesselModified(Vessel thisVessel)
             {
                 CNCLog.Verbose("Active CommNet Vessel '{0}' is staged. Rebuilding the freq list on suriving antennas...", this.Vessel.vesselName);
 
-                //force-rebuild freq list to stop players from abusing LockList
-                this.vesselAntennas = this.readAntennaData();
-                this.FrequencyDict = buildFrequencyList(this.vesselAntennas);
-                this.strongestFreq = computeStrongestFrequency(this.FrequencyDict);
+                if (readCommandData().Count <= 0) //no probe core/command module to "process" signal
+                {
+                    this.controlState = VesselControlState.None;
+                }
+                else
+                {
+                    //force-rebuild freq list to stop players from abusing LockList
+                    this.vesselAntennas = this.readAntennaData();
+                    this.FrequencyDict = buildFrequencyList(this.vesselAntennas);
+                    this.strongestFreq = computeStrongestFrequency(this.FrequencyDict);
+                }
 
                 this.stageActivated = false;
             }
diff --git a/src/CommNetConstellation/CommNetLayer/CNCCommNetwork.cs b/src/CommNetConstellation/CommNetLayer/CNCCommNetwork.cs
index 90e4969..2ddcb18 100644
--- a/src/CommNetConstellation/CommNetLayer/CNCCommNetwork.cs
+++ b/src/CommNetConstellation/CommNetLayer/CNCCommNetwork.cs
@@ -31,38 +31,39 @@ public static bool AreSame(CommNode a, CommNode b)
         /// </summary>
         protected override bool SetNodeConnection(CommNode a, CommNode b)
         {
-            //stop links between ground stations
-            if (a.isHome && b.isHome)
-            {
-                this.Disconnect(a, b, true);
-                return false;
-            }
-
             List<short> aFreqs, bFreqs;
 
-            //each CommNode has at least some frequencies?
             try
             {
+                //stop links between ground stations
+                if (a.isHome && b.isHome)
+                {
+                    this.Disconnect(a, b, true);
+                    return false;
+                }
+
+                //each CommNode has at least some frequencies?
                 aFreqs = CNCCommNetScenario.Instance.getFrequencies(a);
                 bFreqs = CNCCommNetScenario.Instance.getFrequencies(b);
-            }
-            catch (NullReferenceException e) // either CommNode could be a kerbal on EVA
-            {
+
+                //share same frequency?
+                for (int i = 0; i < aFreqs.Count; i++)
+                {
+                    if (bFreqs.Contains(aFreqs[i])) // yes, it does
+                    {
+                        return base.SetNodeConnection(a, b);
+                    }
+                }
+
                 this.Disconnect(a, b, true);
                 return false;
             }
-
-            //share same frequency?
-            for (int i = 0; i < aFreqs.Count; i++)
+            catch (Exception e) // either CommNode could be a kerbal on EVA
             {
-                if (bFreqs.Contains(aFreqs[i])) // yes, it does
-                {
-                    return base.SetNodeConnection(a, b);
-                }
+                //CNCLog.Verbose("Error thrown when checking CommNodes '{0}' & '{1}' - {2}", a.name, b.name, e.Message);
+                this.Disconnect(a, b, true);
+                return false;
             }
-
-            this.Disconnect(a, b, true);
-            return false;
         }
     }
 }