--- a/modules/plugin/base/src/nsPluginHostImpl.cpp
+++ b/modules/plugin/base/src/nsPluginHostImpl.cpp
@@ -763,16 +763,17 @@ nsPluginTag::nsPluginTag(nsPluginTag* aP
       mExtensionsArray[i] = new_str(aPluginTag->mExtensionsArray[i]);
   }
 
   mLibrary = nsnull;
   mCanUnloadLibrary = PR_TRUE;
   mEntryPoint = nsnull;
   mFlags = NS_PLUGIN_FLAG_ENABLED;
   mXPConnected = PR_FALSE;
+  mIsJavaPlugin = aPluginTag->mIsJavaPlugin;
   mFileName = new_str(aPluginTag->mFileName);
   mFullPath = new_str(aPluginTag->mFullPath);
 }
 
 
 ////////////////////////////////////////////////////////////////////////
 nsPluginTag::nsPluginTag(nsPluginInfo* aPluginInfo)
 {
@@ -780,22 +781,26 @@ nsPluginTag::nsPluginTag(nsPluginInfo* a
   mNext = nsnull;
   mName = new_str(aPluginInfo->fName);
   mDescription = new_str(aPluginInfo->fDescription);
   mVariants = aPluginInfo->fVariantCount;
 
   mMimeTypeArray = nsnull;
   mMimeDescriptionArray = nsnull;
   mExtensionsArray = nsnull;
+  mIsJavaPlugin = PR_FALSE;
 
   if(aPluginInfo->fMimeTypeArray != nsnull)
   {
     mMimeTypeArray = new char*[mVariants];
-    for (int i = 0; i < mVariants; i++)
+    for (int i = 0; i < mVariants; i++) {
       mMimeTypeArray[i] = new_str(aPluginInfo->fMimeTypeArray[i]);
+      if (nsPluginHostImpl::IsJavaMIMEType(mMimeTypeArray[i]))
+        mIsJavaPlugin = PR_TRUE;
+    }
   }
 
   if(aPluginInfo->fMimeDescriptionArray != nsnull)
   {
     mMimeDescriptionArray = new char*[mVariants];
     for (int i = 0; i < mVariants; i++) {
       // we should cut off the list of suffixes which the mime
       // description string may have, see bug 53895
@@ -868,26 +873,29 @@ nsPluginTag::nsPluginTag(const char* aNa
     mLastModifiedTime(aLastModifiedTime),
     mFlags(0) // Caller will read in our flags from cache
 {
   mPluginHost = nsnull;
   mName            = new_str(aName);
   mDescription     = new_str(aDescription);
   mFileName        = new_str(aFileName);
   mFullPath        = new_str(aFullPath);
+  mIsJavaPlugin    = PR_FALSE;
 
   if (mVariants) {
     mMimeTypeArray        = new char*[mVariants];
     mMimeDescriptionArray = new char*[mVariants];
     mExtensionsArray      = new char*[mVariants];
 
     for (PRInt32 i = 0; i < aVariants; ++i) {
       mMimeTypeArray[i]        = new_str(aMimeTypes[i]);
       mMimeDescriptionArray[i] = new_str(aMimeDescriptions[i]);
       mExtensionsArray[i]      = new_str(aExtensions[i]);
+      if (nsPluginHostImpl::IsJavaMIMEType(mMimeTypeArray[i]))
+        mIsJavaPlugin = PR_TRUE;
     }
   }
 }
 
 nsPluginTag::~nsPluginTag()
 {
   TryUnloadPlugin(PR_TRUE);
 
@@ -987,16 +995,29 @@ nsPluginTag::GetDisabled(PRBool* aDisabl
 }
 
 NS_IMETHODIMP
 nsPluginTag::SetDisabled(PRBool aDisabled)
 {
   if (HasFlag(NS_PLUGIN_FLAG_ENABLED) == !aDisabled)
     return NS_OK;
 
+  if (mIsJavaPlugin) {
+    nsresult rv;
+    nsCOMPtr<nsIPrefBranch> pref(do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    PRBool javaEnabled;
+    rv = pref->GetBoolPref("security.enable_java", &javaEnabled);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (javaEnabled == aDisabled)
+      return pref->SetBoolPref("security.enable_java", !aDisabled);
+  }
+
   if (aDisabled)
     UnMark(NS_PLUGIN_FLAG_ENABLED);
   else
     Mark(NS_PLUGIN_FLAG_ENABLED);
 
   mPluginHost->UpdatePluginInfo(this);
   return NS_OK;
 }
@@ -3476,17 +3497,17 @@ NS_IMETHODIMP nsPluginHostImpl::Instanti
   } else if (!mJavaEnabled && IsJavaMIMEType(aMimeType)) {
     // Even if we had no Java plugin, if mJavaEnabled is false we should throw
     // here for Java types.  Note that we only need to do this for the case
     // when pluginTag is null; if we had a pluginTag, it would have its
     // NS_PLUGIN_FLAG_ENABLED set the right way.
     return NS_ERROR_NOT_AVAILABLE;
   }
     
-  PRBool isJava = pluginTag && IsJavaPluginTag(pluginTag);
+  PRBool isJava = pluginTag && pluginTag->mIsJavaPlugin;
 
   // Determine if the scheme of this URL is one we can handle internaly because we should
   // only open the initial stream if it's one that we can handle internally. Otherwise
   // |NS_OpenURI| in |InstantiateEmbeddedPlugin| may open up a OS protocal registered helper app
   PRBool bCanHandleInternally = PR_FALSE;
   nsCAutoString scheme;
   if (aURL && NS_SUCCEEDED(aURL->GetScheme(scheme))) {
       nsCAutoString contractID(NS_NETWORK_PROTOCOL_CONTRACTID_PREFIX);
@@ -3640,17 +3661,17 @@ NS_IMETHODIMP nsPluginHostImpl::Instanti
 
   if(FindStoppedPluginForURL(aURI, aOwner) == NS_OK) {
     PLUGIN_LOG(PLUGIN_LOG_NOISY,
     ("nsPluginHostImpl::InstantiateFullPagePlugin FoundStopped mime=%s\n",aMimeType));
 
     nsIPluginInstance* instance;
     aOwner->GetInstance(instance);
     nsPluginTag* pluginTag = FindPluginForType(aMimeType, PR_TRUE);
-    if(!pluginTag || !IsJavaPluginTag(pluginTag))
+    if(!pluginTag || !pluginTag->mIsJavaPlugin)
       NewFullPagePluginStream(aStreamListener, instance);
     NS_IF_RELEASE(instance);
     return NS_OK;
   }
 
   nsresult rv = SetUpPluginInstance(aMimeType, aURI, aOwner);
 
   if (NS_OK == rv)
@@ -3920,17 +3941,17 @@ NS_IMETHODIMP nsPluginHostImpl::TrySetUp
                                                     mimetype))) {
       return NS_ERROR_FAILURE;
     }
   }
   else
     mimetype = aMimeType;
 
   NS_ASSERTION(pluginTag, "Must have plugin tag here!");
-  PRBool isJavaPlugin = IsJavaPluginTag(pluginTag);
+  PRBool isJavaPlugin = pluginTag->mIsJavaPlugin;
 
 #if defined(OJI) && ((defined(XP_UNIX) && !defined(XP_MACOSX)) || defined(XP_OS2))
   // This is a work-around on Unix for a LiveConnect problem (bug 83698).
   // The problem:
   // The proxy JNI needs to be created by the browser. If it is created by
   // someone else (e.g., a plugin) on a different thread, the proxy JNI will
   // not work, and break LiveConnect.
   // Currently, on Unix, when instantiating a Java plugin instance (by calling
@@ -4828,33 +4849,22 @@ static PRBool isUnwantedPlugin(nsPluginT
 
   return PR_TRUE;
 }
 
 ////////////////////////////////////////////////////////////////////////
 PRBool nsPluginHostImpl::IsUnwantedJavaPlugin(nsPluginTag * tag)
 {
 #ifndef OJI
-  return IsJavaPluginTag(tag);
+  return tag->mIsJavaPlugin;
 #else
   return PR_FALSE;
 #endif /* OJI */
 }
 
-PRBool nsPluginHostImpl::IsJavaPluginTag(nsPluginTag * tag)
-{
-  for (PRInt32 i = 0; i < tag->mVariants; ++i) {
-    if (IsJavaMIMEType(tag->mMimeTypeArray[i])) {
-      return PR_TRUE;
-    }
-  }
-
-  return PR_FALSE;
-}
-
 PRBool nsPluginHostImpl::IsJavaMIMEType(const char* aType)
 {
   return aType &&
     ((0 == PL_strncasecmp(aType, "application/x-java-vm",
                           sizeof("application/x-java-vm") - 1)) ||
      (0 == PL_strncasecmp(aType, "application/x-java-applet",
                           sizeof("application/x-java-applet") - 1)) ||
      (0 == PL_strncasecmp(aType, "application/x-java-bean",
@@ -5145,17 +5155,17 @@ nsresult nsPluginHostImpl::ScanPluginsDi
       pluginFile.FreePluginInfo(info);
 
       if(pluginTag == nsnull)
         return NS_ERROR_OUT_OF_MEMORY;
 
       pluginTag->mLibrary = pluginLibrary;
       pluginTag->mLastModifiedTime = fileModTime;
       if (!(oldFlags & NS_PLUGIN_FLAG_ENABLED) ||
-          (IsJavaPluginTag(pluginTag) && !mJavaEnabled))
+          (pluginTag->mIsJavaPlugin && !mJavaEnabled))
         pluginTag->UnMark(NS_PLUGIN_FLAG_ENABLED);
 
       if (oldFlags & NS_PLUGIN_FLAG_BLOCKLISTED)
         pluginTag->Mark(NS_PLUGIN_FLAG_BLOCKLISTED);
 
       // if this is unwanted plugin we are checkin for, or this is a duplicate plugin,
       // add it to our cache info list so we can cache the unwantedness of this plugin
       // when we sync cached plugins to registry
@@ -5785,17 +5795,17 @@ nsPluginHostImpl::ReadPluginInfo()
     }
 
     if (!tag) {
       continue;
     }
 
     // Mark plugin as loaded from cache
     tag->Mark(tagflag | NS_PLUGIN_FLAG_FROMCACHE);
-    if (IsJavaPluginTag(tag)) {
+    if (tag->mIsJavaPlugin) {
       if (mJavaEnabled)
         tag->Mark(NS_PLUGIN_FLAG_ENABLED);
       else
         tag->UnMark(NS_PLUGIN_FLAG_ENABLED);
     }
     PR_LOG(nsPluginLogging::gPluginLog, PLUGIN_LOG_BASIC,
       ("LoadCachedPluginsInfo : Loading Cached plugininfo for %s\n", tag->mFileName));
     tag->mNext = mCachedPlugins;
@@ -6430,17 +6440,17 @@ NS_IMETHODIMP nsPluginHostImpl::Observe(
 
     if (enabled != mJavaEnabled) {
       mJavaEnabled = enabled;
       // We want to keep the java PluginTag around so we'll know that it's
       // actually disabled, not just not present.  So just manually mark it as
       // disabled so at least FindPluginForType/Extension doesn't return
       // anything.
       for (nsPluginTag* cur = mPlugins; cur; cur = cur->mNext) {
-        if (IsJavaPluginTag(cur))
+        if (cur->mIsJavaPlugin)
           cur->SetDisabled(!mJavaEnabled);
       }            
     }
   }
   return NS_OK;
 }
 
 ////////////////////////////////////////////////////////////////////////

--- a/modules/plugin/base/src/nsPluginHostImpl.h
+++ b/modules/plugin/base/src/nsPluginHostImpl.h
@@ -144,16 +144,17 @@ public:
   PRInt32       mVariants;
   char          **mMimeTypeArray;
   char          **mMimeDescriptionArray;
   char          **mExtensionsArray;
   PRLibrary     *mLibrary;
   nsIPlugin     *mEntryPoint;
   PRPackedBool  mCanUnloadLibrary;
   PRPackedBool  mXPConnected;
+  PRPackedBool  mIsJavaPlugin;
   char          *mFileName;
   char          *mFullPath;
   PRInt64       mLastModifiedTime;
 private:
   PRUint32      mFlags;
 };
 
 struct nsActivePlugin
@@ -319,16 +320,20 @@ public:
   AddUnusedLibrary(PRLibrary * aLibrary);
 
   static nsresult GetPluginTempDir(nsIFile **aDir);
 
   // Writes updated plugins settings to disk and unloads the plugin
   // if it is now disabled
   nsresult UpdatePluginInfo(nsPluginTag* aPluginTag);
 
+  // checks whether aTag is a "java" plugin tag (a tag for a plugin
+  // that does Java)
+  static PRBool IsJavaMIMEType(const char *aType);
+
 private:
   NS_IMETHOD
   TrySetUpPluginInstance(const char *aMimeType, nsIURI *aURL, nsIPluginInstanceOwner *aOwner);
 
   nsresult
   LoadXPCOMPlugins(nsIComponentManager* aComponentManager);
 
   nsresult
@@ -398,24 +403,16 @@ private:
   // checks if given plugin is a duplicate of what we already have
   // in the plugin list but found in some different place
   PRBool IsDuplicatePlugin(nsPluginTag * aPluginTag);
 
   // checks whether the given plugin is an unwanted Java plugin
   // (e.g. no OJI support is compiled in)
   PRBool IsUnwantedJavaPlugin(nsPluginTag * aPluginTag);
 
-  // checks whether aTag is a "java" plugin tag (a tag for a plugin
-  // that does Java)
-  PRBool IsJavaPluginTag(nsPluginTag * aPluginTag);
-
-  // checks whether aTag is a "java" plugin tag (a tag for a plugin
-  // that does Java)
-  PRBool IsJavaMIMEType(const char *aType);
-
   nsresult EnsurePrivateDirServiceProvider();
 
   nsresult GetPrompt(nsIPluginInstanceOwner *aOwner, nsIPrompt **aPrompt);
 
   // one-off hack to include nppl3260.dll from the components folder
   nsresult ScanForRealInComponentsFolder(nsIComponentManager * aCompManager);
 
   // calls PostPluginUnloadEvent for each library in mUnusedLibraries