diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index 3979a866b15..4675ea3d0be 100644
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -605,12 +605,6 @@ nsDummyJavaPluginOwner::InvalidateRegion(NPRegion invalidRegion)
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
-NS_IMETHODIMP
-nsDummyJavaPluginOwner::ForceRedraw()
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
 NS_IMETHODIMP
 nsDummyJavaPluginOwner::GetNetscapeWindow(void *value)
 {
diff --git a/dom/plugins/base/nsIPluginInstanceOwner.idl b/dom/plugins/base/nsIPluginInstanceOwner.idl
index eb13982984e..9e5f8f87081 100644
--- a/dom/plugins/base/nsIPluginInstanceOwner.idl
+++ b/dom/plugins/base/nsIPluginInstanceOwner.idl
@@ -49,7 +49,9 @@ class nsPluginEvent;
 
 [ptr] native nsNPAPIPluginInstancePtr(nsNPAPIPluginInstance);
 
-[uuid(17E89C1F-AE62-448E-83D5-C33FA6E07A19)]
+// Do not make this interface scriptable, because the virtual functions in C++
+// blocks will make script call the wrong functions.
+[uuid(23bd0a76-a5dc-4a1d-be76-13d7a0dfd9ff)]
 interface nsIPluginInstanceOwner : nsISupports
 {
   /**
@@ -116,11 +118,6 @@ interface nsIPluginInstanceOwner : nsISupports
    */
   void invalidateRegion(in NPRegion aRegion);
 
-  /**
-   * Force a redraw
-   */
-  void forceRedraw();
-
   /**
    * Get NetscapeWindow, corresponds to NPNVnetscapeWindow
    */
diff --git a/dom/plugins/base/nsNPAPIPlugin.cpp b/dom/plugins/base/nsNPAPIPlugin.cpp
index 109430b8ce8..ec99dcb58ff 100644
--- a/dom/plugins/base/nsNPAPIPlugin.cpp
+++ b/dom/plugins/base/nsNPAPIPlugin.cpp
@@ -1308,22 +1308,6 @@ _invalidateregion(NPP npp, NPRegion invalidRegion)
 void NP_CALLBACK
 _forceredraw(NPP npp)
 {
-  if (!NS_IsMainThread()) {
-    NPN_PLUGIN_LOG(PLUGIN_LOG_ALWAYS,("NPN_forceredraw called from the wrong thread\n"));
-    return;
-  }
-  NPN_PLUGIN_LOG(PLUGIN_LOG_NORMAL, ("NPN_ForceDraw: npp=%p\n", (void*)npp));
-
-  if (!npp || !npp->ndata) {
-    NS_WARNING("_forceredraw: npp or npp->ndata == 0");
-    return;
-  }
-
-  nsNPAPIPluginInstance *inst = (nsNPAPIPluginInstance*)npp->ndata;
-
-  PluginDestructionGuard guard(inst);
-
-  inst->ForceRedraw();
 }
 
 NPObject* NP_CALLBACK
diff --git a/dom/plugins/base/nsNPAPIPluginInstance.cpp b/dom/plugins/base/nsNPAPIPluginInstance.cpp
index 3f81a3dff96..0f90ad6ded6 100644
--- a/dom/plugins/base/nsNPAPIPluginInstance.cpp
+++ b/dom/plugins/base/nsNPAPIPluginInstance.cpp
@@ -1349,20 +1349,6 @@ nsNPAPIPluginInstance::InvalidateRegion(NPRegion invalidRegion)
   return owner->InvalidateRegion(invalidRegion);
 }
 
-nsresult
-nsNPAPIPluginInstance::ForceRedraw()
-{
-  if (RUNNING != mRunning)
-    return NS_OK;
-
-  nsCOMPtr<nsIPluginInstanceOwner> owner;
-  GetOwner(getter_AddRefs(owner));
-  if (!owner)
-    return NS_ERROR_FAILURE;
-
-  return owner->ForceRedraw();
-}
-
 nsresult
 nsNPAPIPluginInstance::GetMIMEType(const char* *result)
 {
diff --git a/dom/plugins/base/nsNPAPIPluginInstance.h b/dom/plugins/base/nsNPAPIPluginInstance.h
index c56439fb431..ca13f71accf 100644
--- a/dom/plugins/base/nsNPAPIPluginInstance.h
+++ b/dom/plugins/base/nsNPAPIPluginInstance.h
@@ -115,7 +115,6 @@ public:
   nsresult GetPluginAPIVersion(PRUint16* version);
   nsresult InvalidateRect(NPRect *invalidRect);
   nsresult InvalidateRegion(NPRegion invalidRegion);
-  nsresult ForceRedraw();
   nsresult GetMIMEType(const char* *result);
   nsresult GetJSContext(JSContext* *outContext);
   nsresult GetOwner(nsIPluginInstanceOwner **aOwner);
diff --git a/dom/plugins/base/nsPluginInstanceOwner.cpp b/dom/plugins/base/nsPluginInstanceOwner.cpp
index c566b65e473..0479601da7d 100644
--- a/dom/plugins/base/nsPluginInstanceOwner.cpp
+++ b/dom/plugins/base/nsPluginInstanceOwner.cpp
@@ -674,11 +674,6 @@ NS_IMETHODIMP nsPluginInstanceOwner::InvalidateRegion(NPRegion invalidRegion)
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
-NS_IMETHODIMP nsPluginInstanceOwner::ForceRedraw()
-{
-  return NS_OK;
-}
-
 NS_IMETHODIMP nsPluginInstanceOwner::GetNetscapeWindow(void *value)
 {
   if (!mObjectFrame) {