diff --git a/mozilla/content/html/content/src/nsHTMLImageElement.cpp b/mozilla/content/html/content/src/nsHTMLImageElement.cpp
index 92bf7c80516..72c0efc5d35 100644
--- a/mozilla/content/html/content/src/nsHTMLImageElement.cpp
+++ b/mozilla/content/html/content/src/nsHTMLImageElement.cpp
@@ -723,10 +723,24 @@ nsHTMLImageElement::SetSrc(const nsAString& aSrc)
     }
   }
 
+  nsCOMPtr<imgIRequest> oldCurrentRequest = mCurrentRequest;
+  
   // Call ImageURIChanged first so that our image load will kick off
   // before the SetAttr triggers a reflow
   ImageURIChanged(aSrc);
 
+  if (mCurrentRequest && !mPendingRequest &&
+      oldCurrentRequest != mCurrentRequest) {
+    // We have a current request, and it's not the same one as we used
+    // to have, and we have no pending request.  So imglib already had
+    // that image.  Reset the animation on it -- see bug 210001
+    nsCOMPtr<imgIContainer> container;
+    mCurrentRequest->GetImage(getter_AddRefs(container));
+    if (container) {
+      container->ResetAnimation();
+    }
+  }
+  
   return nsGenericHTMLLeafElement::SetAttr(kNameSpaceID_None,
                                            nsHTMLAtoms::src, aSrc, PR_TRUE);
 }
diff --git a/mozilla/layout/base/nsImageLoader.cpp b/mozilla/layout/base/nsImageLoader.cpp
index 743b8bf52bf..b14979c542a 100644
--- a/mozilla/layout/base/nsImageLoader.cpp
+++ b/mozilla/layout/base/nsImageLoader.cpp
@@ -141,6 +141,8 @@ NS_IMETHODIMP nsImageLoader::OnStartContainer(imgIRequest *aRequest,
      *   one loop = 2
      */
     aImage->SetAnimationMode(mPresContext->ImageAnimationMode());
+    // Ensure the animation (if any) is started.
+    aImage->StartAnimation();
   }
   return NS_OK;
 }
diff --git a/mozilla/layout/base/src/nsImageLoader.cpp b/mozilla/layout/base/src/nsImageLoader.cpp
index 743b8bf52bf..b14979c542a 100644
--- a/mozilla/layout/base/src/nsImageLoader.cpp
+++ b/mozilla/layout/base/src/nsImageLoader.cpp
@@ -141,6 +141,8 @@ NS_IMETHODIMP nsImageLoader::OnStartContainer(imgIRequest *aRequest,
      *   one loop = 2
      */
     aImage->SetAnimationMode(mPresContext->ImageAnimationMode());
+    // Ensure the animation (if any) is started.
+    aImage->StartAnimation();
   }
   return NS_OK;
 }
diff --git a/mozilla/layout/generic/nsBulletFrame.cpp b/mozilla/layout/generic/nsBulletFrame.cpp
index 9e22f338e59..c02c078e9dd 100644
--- a/mozilla/layout/generic/nsBulletFrame.cpp
+++ b/mozilla/layout/generic/nsBulletFrame.cpp
@@ -1711,6 +1711,12 @@ NS_IMETHODIMP nsBulletFrame::OnStartContainer(imgIRequest *aRequest,
     }
   }
 
+  // Handle animations
+  aImage->SetAnimationMode(mPresContext->ImageAnimationMode());
+  // Ensure the animation (if any) is started.
+  aImage->StartAnimation();
+
+  
   return NS_OK;
 }
 
diff --git a/mozilla/layout/generic/nsImageFrame.cpp b/mozilla/layout/generic/nsImageFrame.cpp
index fcdd1d5e30f..c9f33bef293 100644
--- a/mozilla/layout/generic/nsImageFrame.cpp
+++ b/mozilla/layout/generic/nsImageFrame.cpp
@@ -329,11 +329,14 @@ nsImageFrame::Init(nsIPresContext*  aPresContext,
   }
   // If we already have an image container, OnStartContainer won't be called
   // Set the animation mode here
-  nsCOMPtr<imgIContainer> image;
   if (currentRequest) {
+    nsCOMPtr<imgIContainer> image;
     currentRequest->GetImage(getter_AddRefs(image));
-    if (image)
+    if (image) {
       image->SetAnimationMode(mPresContext->ImageAnimationMode());
+      // Ensure the animation (if any) is started.
+      image->StartAnimation();
+    }
   }
 
   return rv;
@@ -538,6 +541,8 @@ nsImageFrame::OnStartContainer(imgIRequest *aRequest, imgIContainer *aImage)
    *   one loop = 2
    */
   aImage->SetAnimationMode(mPresContext->ImageAnimationMode());
+  // Ensure the animation (if any) is started.
+  aImage->StartAnimation();
 
   if (IsPendingLoad(aRequest)) {
     // We don't care
diff --git a/mozilla/layout/html/base/src/nsBulletFrame.cpp b/mozilla/layout/html/base/src/nsBulletFrame.cpp
index 9e22f338e59..c02c078e9dd 100644
--- a/mozilla/layout/html/base/src/nsBulletFrame.cpp
+++ b/mozilla/layout/html/base/src/nsBulletFrame.cpp
@@ -1711,6 +1711,12 @@ NS_IMETHODIMP nsBulletFrame::OnStartContainer(imgIRequest *aRequest,
     }
   }
 
+  // Handle animations
+  aImage->SetAnimationMode(mPresContext->ImageAnimationMode());
+  // Ensure the animation (if any) is started.
+  aImage->StartAnimation();
+
+  
   return NS_OK;
 }
 
diff --git a/mozilla/layout/html/base/src/nsImageFrame.cpp b/mozilla/layout/html/base/src/nsImageFrame.cpp
index fcdd1d5e30f..c9f33bef293 100644
--- a/mozilla/layout/html/base/src/nsImageFrame.cpp
+++ b/mozilla/layout/html/base/src/nsImageFrame.cpp
@@ -329,11 +329,14 @@ nsImageFrame::Init(nsIPresContext*  aPresContext,
   }
   // If we already have an image container, OnStartContainer won't be called
   // Set the animation mode here
-  nsCOMPtr<imgIContainer> image;
   if (currentRequest) {
+    nsCOMPtr<imgIContainer> image;
     currentRequest->GetImage(getter_AddRefs(image));
-    if (image)
+    if (image) {
       image->SetAnimationMode(mPresContext->ImageAnimationMode());
+      // Ensure the animation (if any) is started.
+      image->StartAnimation();
+    }
   }
 
   return rv;
@@ -538,6 +541,8 @@ nsImageFrame::OnStartContainer(imgIRequest *aRequest, imgIContainer *aImage)
    *   one loop = 2
    */
   aImage->SetAnimationMode(mPresContext->ImageAnimationMode());
+  // Ensure the animation (if any) is started.
+  aImage->StartAnimation();
 
   if (IsPendingLoad(aRequest)) {
     // We don't care
diff --git a/mozilla/layout/xul/base/src/nsImageBoxFrame.cpp b/mozilla/layout/xul/base/src/nsImageBoxFrame.cpp
index ce924c818aa..ab6d4a219fc 100644
--- a/mozilla/layout/xul/base/src/nsImageBoxFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsImageBoxFrame.cpp
@@ -724,6 +724,9 @@ NS_IMETHODIMP nsImageBoxFrame::OnStartContainer(imgIRequest *request,
   // If we have no prescontext, what's going on?
   NS_ENSURE_TRUE(mPresContext, NS_ERROR_UNEXPECTED);
 
+  // Ensure the animation (if any) is started
+  image->StartAnimation();
+
   mHasImage = PR_TRUE;
   mSizeFrozen = PR_FALSE;
 
diff --git a/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp b/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp
index b08bb6e2e4f..d238bd034d1 100644
--- a/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp
+++ b/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp
@@ -3904,6 +3904,8 @@ NS_IMETHODIMP nsTreeImageListener::OnStartDecode(imgIRequest *aRequest)
 NS_IMETHODIMP nsTreeImageListener::OnStartContainer(imgIRequest *aRequest,
                                                     imgIContainer *aImage)
 {
+  // Ensure the animation (if any) is started
+  aImage->StartAnimation();
   return NS_OK;
 }
 
diff --git a/mozilla/modules/libpr0n/src/imgRequest.cpp b/mozilla/modules/libpr0n/src/imgRequest.cpp
index 55b8f5fa8b3..9313255fa00 100644
--- a/mozilla/modules/libpr0n/src/imgRequest.cpp
+++ b/mozilla/modules/libpr0n/src/imgRequest.cpp
@@ -223,10 +223,9 @@ nsresult imgRequest::NotifyProxyListener(imgRequestProxy *proxy)
     proxy->OnStopDecode(GetResultFromImageStatus(mImageStatus), nsnull);
 
   if (mImage && (mObservers.Count() == 1)) {
-    LOG_MSG(gImgLog, "imgRequest::AddProxy", "starting animation");
+    LOG_MSG(gImgLog, "imgRequest::AddProxy", "resetting animation");
 
     mImage->ResetAnimation();
-    mImage->StartAnimation();
   }
 
   if (mState & onStopRequest) {