diff --git a/src/uas/QGCUASParamManager.cc b/src/uas/QGCUASParamManager.cc
index 1dd6050c57c226641758d660008163829b547d42..c1b29e88f18bef2f4082a63a10c4257ddf3cc3f0 100644
--- a/src/uas/QGCUASParamManager.cc
+++ b/src/uas/QGCUASParamManager.cc
@@ -8,7 +8,9 @@
 
 QGCUASParamManager::QGCUASParamManager(UASInterface* uas, QWidget *parent) :
     QWidget(parent),
-    mav(uas)
+    mav(uas),
+    paramDataModel(NULL),
+    paramCommsMgr(NULL)
 {
     paramDataModel = uas->getParamDataModel();
     paramCommsMgr = uas->getParamCommsMgr();
@@ -18,25 +20,6 @@ QGCUASParamManager::QGCUASParamManager(UASInterface* uas, QWidget *parent) :
     loadParamMetaInfoCSV();
 
 
-//    // Connect retransmission guard
-//    connect(this, SIGNAL(parameterUpdateRequested(int,QString)),
-//            this, SLOT(requestParameterUpdate(int,QString)));
-
-//    //TODO connect in paramCommsMgr instead
-//    connect(this, SIGNAL(parameterUpdateRequestedById(int,int)),
-//            mav, SLOT(requestParameter(int,int)));
-
-    // New parameters from UAS
-
-    void parameterUpdated(int compId, QString paramName, QVariant value);
-
-
-//    connect(uas, SIGNAL(parameterChanged(int,int,int,int,QString,QVariant)),
-//            this, SLOT(receivedParameterUpdate(int,int,int,int,QString,QVariant)));
-
-
-
-
 
 }
 
diff --git a/src/uas/UASParameterDataModel.cc b/src/uas/UASParameterDataModel.cc
index 9815ce77798147bee5b0dd5cce230ca6ef85865d..96d7479f0b59fb96a2c29501a05681d806e37fa7 100644
--- a/src/uas/UASParameterDataModel.cc
+++ b/src/uas/UASParameterDataModel.cc
@@ -11,7 +11,8 @@
 UASParameterDataModel::UASParameterDataModel(QObject *parent) :
     QObject(parent)
 {
-
+    onboardParameters.clear();
+    pendingParameters.clear();
 
 }
 
diff --git a/src/uas/UASParameterDataModel.h b/src/uas/UASParameterDataModel.h
index 219eff900b2d0d9e79db96f7848911acdf1e6e78..535cc03082c530231dac32e9e12698c825dc7688 100644
--- a/src/uas/UASParameterDataModel.h
+++ b/src/uas/UASParameterDataModel.h
@@ -14,7 +14,6 @@ public:
     explicit UASParameterDataModel(QObject *parent = 0);
     
 
-    int getTotalOnboardParams() { return totalOnboardParameters; }
     //Parameter meta info
     bool isParamMinKnown(const QString& param) { return paramMin.contains(param); }
     virtual bool isValueLessThanParamMin(const QString& param, double dblVal);
@@ -97,7 +96,6 @@ protected:
     int     uasId; ///< The UAS / MAV to which this data model pertains
     QMap<int, QMap<QString, QVariant>* > pendingParameters; ///< Changed values that have not yet been transmitted to the UAS, by component ID
     QMap<int, QMap<QString, QVariant>* > onboardParameters; ///< All parameters confirmed to be stored onboard the UAS, by component ID
-    int totalOnboardParameters;///< The known count of onboard parameters, may not match onboardParameters until all params are received
 
     // Tooltip data structures
     QMap<QString, QString> paramDescriptions; ///< Tooltip values
diff --git a/src/ui/designer/QGCParamSlider.cc b/src/ui/designer/QGCParamSlider.cc
index e927dea03200976d9d2528595e7129eedefd8acf..32b236a4b853e3cb6a55f4fb60ad587b1605be1b 100644
--- a/src/ui/designer/QGCParamSlider.cc
+++ b/src/ui/designer/QGCParamSlider.cc
@@ -175,6 +175,9 @@ void QGCParamSlider::selectParameter(int paramIndex)
 {
     // Set name
     parameterName = ui->editSelectParamComboBox->itemText(paramIndex);
+    if (parameterName.isEmpty()) {
+        return;
+    }
 
     // Update min and max values if available
     if (uas) {