diff --git a/Card3D/Card3D.cpp b/Card3D/Card3D.cpp
index bcadd849..a361e6dd 100644
--- a/Card3D/Card3D.cpp
+++ b/Card3D/Card3D.cpp
@@ -2001,7 +2001,10 @@ Card3DPlugin::changedParam(const InstanceChangedArgs &args,
 {
     //const double time = args.time;
     if ( (paramName == kParamPremult) && (args.reason == eChangeUserEdit) ) {
-        _srcClipChanged->setValue(true);
+        // Only set if necessary
+        if (!_srcClipChanged->getValue()) {
+            _srcClipChanged->setValue(true);
+        }
     } else if (paramName == kParamCamEnable) {
         updateVisibility();
     } else if (paramName == kParamOutputFormat) {
diff --git a/GodRays/GodRays.cpp b/GodRays/GodRays.cpp
index 6b790d2e..2fea49f6 100644
--- a/GodRays/GodRays.cpp
+++ b/GodRays/GodRays.cpp
@@ -713,6 +713,7 @@ GodRaysPlugin::getInverseTransformCanonical(double time,
 void
 GodRaysPlugin::resetCenter(double time)
 {
+    // Note: same code as TransformPlugin::resetCenter()
     if (!_srcClip || !_srcClip->isConnected()) {
         return;
     }
@@ -774,28 +775,36 @@ GodRaysPlugin::resetCenter(double time)
     OfxPointD newCenter;
     newCenter.x = (rod.x1 + rod.x2) / 2;
     newCenter.y = (rod.y1 + rod.y2) / 2;
-    EditBlock eb(*this, "resetCenter");
-    if (_center) {
-        _center->setValue(newCenter.x, newCenter.y);
-    }
-    if (_translate) {
-        double dxrot = newCenter.x - center.x;
-        double dyrot = newCenter.y - center.y;
-        Point3D dRot;
-        dRot.x = dxrot;
-        dRot.y = dyrot;
-        dRot.z = 1;
-        dRot = Rinv * dRot;
-        if (dRot.z != 0) {
-            dRot.x /= dRot.z;
-            dRot.y /= dRot.z;
+    if (newCenter.x != center.x || newCenter.y != center.y) {
+        bool editBlockNecessary = false;
+        OfxPointD newTranslate = {0., 0.};
+        if (_translate) {
+            double dxrot = newCenter.x - center.x;
+            double dyrot = newCenter.y - center.y;
+            Point3D dRot;
+            dRot.x = dxrot;
+            dRot.y = dyrot;
+            dRot.z = 1;
+            dRot = Rinv * dRot;
+            if (dRot.z != 0) {
+                dRot.x /= dRot.z;
+                dRot.y /= dRot.z;
+            }
+            double dx = dRot.x;
+            double dy = dRot.y;
+            newTranslate.x = translate.x + dx - dxrot;
+            newTranslate.y = translate.y + dy - dyrot;
+            if (newTranslate.x != translate.x || newTranslate.y != translate.y) {
+                editBlockNecessary = true;
+            }
+        }
+        EditBlock eb(*this, "resetCenter", editBlockNecessary);
+        if (_center) {
+            _center->setValue(newCenter.x, newCenter.y);
+        }
+        if (_translate) {
+            _translate->setValue(newTranslate.x, newTranslate.y);
         }
-        double dx = dRot.x;
-        double dy = dRot.y;
-        OfxPointD newTranslate;
-        newTranslate.x = translate.x + dx - dxrot;
-        newTranslate.y = translate.y + dy - dyrot;
-        _translate->setValue(newTranslate.x, newTranslate.y);
     }
 } // GodRaysPlugin::resetCenter
 
@@ -805,7 +814,10 @@ GodRaysPlugin::changedParam(const InstanceChangedArgs &args,
 {
     if (paramName == kParamTransformResetCenterOld) {
         resetCenter(args.time);
-        _centerChanged->setValue(false);
+        // Only set if necessary
+        if (_centerChanged->getValue()) {
+            _centerChanged->setValue(false);
+        }
     } else if ( (paramName == kParamTransformTranslateOld) ||
                 ( paramName == kParamTransformRotateOld) ||
                 ( paramName == kParamTransformScaleOld) ||
@@ -816,7 +828,10 @@ GodRaysPlugin::changedParam(const InstanceChangedArgs &args,
                 ( paramName == kParamTransformCenterOld) ) {
         if ( (paramName == kParamTransformCenterOld) &&
              ( (args.reason == eChangeUserEdit) || (args.reason == eChangePluginEdit) ) ) {
-            _centerChanged->setValue(true);
+            // Only set if necessary
+            if (!_centerChanged->getValue()) {
+                _centerChanged->setValue(true);
+            }
         }
         changedTransform(args);
     } else if ( (paramName == kParamPremult) && (args.reason == eChangeUserEdit) ) {
diff --git a/SupportExt b/SupportExt
index fcd777bb..8aff0b0a 160000
--- a/SupportExt
+++ b/SupportExt
@@ -1 +1 @@
-Subproject commit fcd777bb2b3ca00def5e5693cbf09f8df9e2304b
+Subproject commit 8aff0b0ae59f50fd9a06abb560367ef7534730cf
diff --git a/Transform/Transform.cpp b/Transform/Transform.cpp
index 83f09b5a..57ad5488 100644
--- a/Transform/Transform.cpp
+++ b/Transform/Transform.cpp
@@ -330,28 +330,36 @@ TransformPlugin::resetCenter(double time)
     OfxPointD newCenter;
     newCenter.x = (rod.x1 + rod.x2) / 2;
     newCenter.y = (rod.y1 + rod.y2) / 2;
-    EditBlock eb(*this, "resetCenter");
-    if (_center) {
-        _center->setValue(newCenter.x, newCenter.y);
-    }
-    if (_translate) {
-        double dxrot = newCenter.x - center.x;
-        double dyrot = newCenter.y - center.y;
-        Point3D dRot;
-        dRot.x = dxrot;
-        dRot.y = dyrot;
-        dRot.z = 1;
-        dRot = Rinv * dRot;
-        if (dRot.z != 0) {
-            dRot.x /= dRot.z;
-            dRot.y /= dRot.z;
+    if (newCenter.x != center.x || newCenter.y != center.y) {
+        bool editBlockNecessary = false;
+        OfxPointD newTranslate = {0., 0.};
+        if (_translate) {
+            double dxrot = newCenter.x - center.x;
+            double dyrot = newCenter.y - center.y;
+            Point3D dRot;
+            dRot.x = dxrot;
+            dRot.y = dyrot;
+            dRot.z = 1;
+            dRot = Rinv * dRot;
+            if (dRot.z != 0) {
+                dRot.x /= dRot.z;
+                dRot.y /= dRot.z;
+            }
+            double dx = dRot.x;
+            double dy = dRot.y;
+            newTranslate.x = translate.x + dx - dxrot;
+            newTranslate.y = translate.y + dy - dyrot;
+            if (newTranslate.x != translate.x || newTranslate.y != translate.y) {
+                editBlockNecessary = true;
+            }
+        }
+        EditBlock eb(*this, "resetCenter", editBlockNecessary);
+        if (_center) {
+            _center->setValue(newCenter.x, newCenter.y);
+        }
+        if (_translate) {
+            _translate->setValue(newTranslate.x, newTranslate.y);
         }
-        double dx = dRot.x;
-        double dy = dRot.y;
-        OfxPointD newTranslate;
-        newTranslate.x = translate.x + dx - dxrot;
-        newTranslate.y = translate.y + dy - dyrot;
-        _translate->setValue(newTranslate.x, newTranslate.y);
     }
 } // TransformPlugin::resetCenter
 
@@ -361,7 +369,10 @@ TransformPlugin::changedParam(const InstanceChangedArgs &args,
 {
     if (paramName == kParamTransformResetCenterOld) {
         resetCenter(args.time);
-        _centerChanged->setValue(false);
+        // Only set if necessary
+        if (_centerChanged->getValue()) {
+            _centerChanged->setValue(false);
+        }
     } else if ( (paramName == kParamTransformTranslateOld) ||
                 ( paramName == kParamTransformRotateOld) ||
                 ( paramName == kParamTransformScaleOld) ||
@@ -372,11 +383,17 @@ TransformPlugin::changedParam(const InstanceChangedArgs &args,
                 ( paramName == kParamTransformCenterOld) ) {
         if ( (paramName == kParamTransformCenterOld) &&
              ( (args.reason == eChangeUserEdit) || (args.reason == eChangePluginEdit) ) ) {
-            _centerChanged->setValue(true);
+            // Only set if necessary
+            if (!_centerChanged->getValue()) {
+                _centerChanged->setValue(true);
+            }
         }
         changedTransform(args);
     } else if ( (paramName == kParamPremult) && (args.reason == eChangeUserEdit) ) {
-        _srcClipChanged->setValue(true);
+        // Only set if necessary
+        if (!_srcClipChanged->getValue()) {
+            _srcClipChanged->setValue(true);
+        }
     } else {
         Transform3x3Plugin::changedParam(args, paramName);
     }
@@ -388,7 +405,7 @@ TransformPlugin::changedClip(const InstanceChangedArgs &args,
 {
     if ( (clipName == kOfxImageEffectSimpleSourceClipName) &&
          _srcClip && _srcClip->isConnected() &&
-         !_centerChanged->getValueAtTime(args.time) &&
+         !_centerChanged->getValue() &&
          ( args.reason == eChangeUserEdit) ) {
         resetCenter(args.time);
     }