diff --git a/plugins/Correlation.java b/plugins/Correlation.java
index c9dad7b..7fdb840 100644
--- a/plugins/Correlation.java
+++ b/plugins/Correlation.java
@@ -27,6 +27,10 @@ public class Correlation extends Panel {
     public void onStateChange(State state, State former) {
         buttonStart.setEnabled(state==State.Ready);
         buttonStop.setEnabled(state==State.Busy);
+        textDevX.setEnabled(state==State.Ready);
+        textDevY.setEnabled(state==State.Ready);
+        spinnerInterval.setEnabled(state==State.Ready);
+        spinnerWindow.setEnabled(state==State.Ready);
     }
 
     @Override
diff --git a/script/Correlation/Correlation.py b/script/Correlation/Correlation.py
index 1af9c52..a411f34 100644
--- a/script/Correlation/Correlation.py
+++ b/script/Correlation/Correlation.py
@@ -23,6 +23,10 @@ if isinstance(dy, basestring):
 sd=p.getSeries(0)
 sd.setLinesVisible(False)
 sd.setPointSize(4)
+
+if globals().has_key("marker")
+    p.removeMarker(marker)
+
 marker=None
 
 while(True):