diff --git a/rtgui/lensgeom.cc b/rtgui/lensgeom.cc
index d50a16f45..1d39ced42 100644
--- a/rtgui/lensgeom.cc
+++ b/rtgui/lensgeom.cc
@@ -43,6 +43,11 @@ LensGeometry::LensGeometry () : FoldableToolPanel(this, "lensgeom", M("TP_LENSGE
     show_all ();
 }
 
+LensGeometry::~LensGeometry ()
+{
+    g_idle_remove_by_data(this);
+}
+
 void LensGeometry::read (const ProcParams* pp, const ParamsEdited* pedited)
 {
 
@@ -116,16 +121,23 @@ void LensGeometry::setBatchMode (bool batchMode)
 
 void LensGeometry::disableAutoFillIfActive ()
 {
+    g_idle_add(doDisableAutoFillIfActive, this);
+}
 
-    if (!batchMode) {
-        if (fill->get_active()) {
-            fillConn.block (true);
-            fill->set_active(false);
-            if (listener) {
-                listener->panelChanged (EvTransAutoFill, M("GENERAL_DISABLED"));
+int LensGeometry::doDisableAutoFillIfActive (void* data)
+{
+    GThreadLock lock; // Is this really needed?
+
+    LensGeometry* const instance = static_cast<LensGeometry*>(data);
+
+    if (!instance->batchMode) {
+        if (instance->fill->get_active()) {
+            instance->fillConn.block (true);
+            instance->fill->set_active(false);
+            if (instance->listener) {
+                instance->listener->panelChanged (EvTransAutoFill, M("GENERAL_DISABLED"));
             }
-            fillConn.block (false);
+            instance->fillConn.block (false);
         }
     }
-
 }
diff --git a/rtgui/lensgeom.h b/rtgui/lensgeom.h
index fe21feb6a..51a6e108c 100644
--- a/rtgui/lensgeom.h
+++ b/rtgui/lensgeom.h
@@ -32,11 +32,12 @@ protected:
     Gtk::CheckButton*   fill;
     bool                lastFill;
     sigc::connection    fillConn;
-    ToolParamBlock*           packBox;
+    ToolParamBlock*     packBox;
 
 public:
 
     LensGeometry ();
+    ~LensGeometry ();
 
     Gtk::Box* getPackBox ()
     {
@@ -54,6 +55,10 @@ public:
         rlistener = l;
     }
     void disableAutoFillIfActive ();
+
+private:
+    static int doDisableAutoFillIfActive (void* data);
+
 };
 
 #endif
diff --git a/rtgui/myflatcurve.cc b/rtgui/myflatcurve.cc
index fe53565d2..0bc3bd533 100644
--- a/rtgui/myflatcurve.cc
+++ b/rtgui/myflatcurve.cc
@@ -1807,6 +1807,7 @@ void MyFlatCurve::setPoints (const std::vector<double>& p)
     stopNumericalAdjustment();
     FlatCurveType t = (FlatCurveType)p[ix++];
     curve.type = t;
+    lit_point = -1;
 
     if (t == FCT_MinMaxCPoints) {
         curve.x.clear ();