diff --git a/content/html/content/src/nsHTMLInputElement.cpp b/content/html/content/src/nsHTMLInputElement.cpp
index 7329b85b200b..995988163344 100644
--- a/content/html/content/src/nsHTMLInputElement.cpp
+++ b/content/html/content/src/nsHTMLInputElement.cpp
@@ -340,7 +340,7 @@ nsHTMLInputElement::Clone(nsINodeInfo *aNodeInfo, nsINode **aResult) const
       if (GET_BOOLBIT(mBitField, BF_CHECKED_CHANGED)) {
         // We no longer have our original checked state.  Set our
         // checked state on the clone.
-        it->DoSetChecked(GetChecked(), PR_FALSE);
+        it->DoSetChecked(GetChecked(), PR_FALSE, PR_TRUE);
       }
       break;
     case NS_FORM_INPUT_IMAGE:
@@ -428,7 +428,7 @@ nsHTMLInputElement::AfterSetAttr(PRInt32 aNameSpaceID, nsIAtom* aName,
       } else {
         PRBool defaultChecked;
         GetDefaultChecked(&defaultChecked);
-        DoSetChecked(defaultChecked);
+        DoSetChecked(defaultChecked, PR_TRUE, PR_TRUE);
         SetCheckedChanged(PR_FALSE);
       }
     }
@@ -1024,20 +1024,21 @@ nsHTMLInputElement::GetCheckedChanged()
 NS_IMETHODIMP
 nsHTMLInputElement::SetChecked(PRBool aChecked)
 {
-  return DoSetChecked(aChecked);
+  return DoSetChecked(aChecked, PR_TRUE, PR_TRUE);
 }
 
 nsresult
-nsHTMLInputElement::DoSetChecked(PRBool aChecked, PRBool aNotify)
+nsHTMLInputElement::DoSetChecked(PRBool aChecked, PRBool aNotify,
+                                 PRBool aSetValueChanged)
 {
   nsresult rv = NS_OK;
 
-  //
   // If the user or JS attempts to set checked, whether it actually changes the
   // value or not, we say the value was changed so that defaultValue don't
   // affect it no more.
-  //
-  DoSetCheckedChanged(PR_TRUE, aNotify);
+  if (aSetValueChanged) {
+    DoSetCheckedChanged(PR_TRUE, aNotify);
+  }
 
   //
   // Don't do anything if we're not changing whether it's checked (it would
@@ -1493,7 +1494,7 @@ nsHTMLInputElement::PreHandleEvent(nsEventChainPreVisitor& aVisitor)
           }
 
           GetChecked(&originalCheckedValue);
-          DoSetChecked(!originalCheckedValue);
+          DoSetChecked(!originalCheckedValue, PR_TRUE, PR_TRUE);
           SET_BOOLBIT(mBitField, BF_CHECKED_IS_TOGGLED, PR_TRUE);
         }
         break;
@@ -1513,7 +1514,7 @@ nsHTMLInputElement::PreHandleEvent(nsEventChainPreVisitor& aVisitor)
 
           originalCheckedValue = GetChecked();
           if (!originalCheckedValue) {
-            DoSetChecked(PR_TRUE);
+            DoSetChecked(PR_TRUE, PR_TRUE, PR_TRUE);
             SET_BOOLBIT(mBitField, BF_CHECKED_IS_TOGGLED, PR_TRUE);
           }
         }
@@ -1674,13 +1675,13 @@ nsHTMLInputElement::PostHandleEvent(nsEventChainPostVisitor& aVisitor)
         // If this one is no longer a radio button we must reset it back to
         // false to cancel the action.  See how the web of hack grows?
         if (mType != NS_FORM_INPUT_RADIO) {
-          DoSetChecked(PR_FALSE);
+          DoSetChecked(PR_FALSE, PR_TRUE, PR_TRUE);
         }
       } else if (oldType == NS_FORM_INPUT_CHECKBOX) {
         PRBool originalIndeterminateValue =
           !!(aVisitor.mItemFlags & NS_ORIGINAL_INDETERMINATE_VALUE);
         SetIndeterminateInternal(originalIndeterminateValue, PR_FALSE);
-        DoSetChecked(originalCheckedValue);
+        DoSetChecked(originalCheckedValue, PR_TRUE, PR_TRUE);
       }
     } else {
       FireOnChange();
@@ -2380,7 +2381,7 @@ nsHTMLInputElement::SetDefaultValueAsValue()
     {
       PRBool resetVal;
       GetDefaultChecked(&resetVal);
-      return DoSetChecked(resetVal);
+      return DoSetChecked(resetVal, PR_TRUE, PR_FALSE);
     }
     case NS_FORM_INPUT_SEARCH:
     case NS_FORM_INPUT_PASSWORD:
@@ -2664,7 +2665,7 @@ nsHTMLInputElement::DoneCreatingElement()
       GET_BOOLBIT(mBitField, BF_SHOULD_INIT_CHECKED)) {
     PRBool resetVal;
     GetDefaultChecked(&resetVal);
-    DoSetChecked(resetVal, PR_FALSE);
+    DoSetChecked(resetVal, PR_FALSE, PR_TRUE);
     DoSetCheckedChanged(PR_FALSE, PR_FALSE);
   }
 
@@ -2719,7 +2720,7 @@ nsHTMLInputElement::RestoreState(nsPresState* aState)
         {
           if (inputState->IsCheckedSet()) {
             restoredCheckedState = PR_TRUE;
-            DoSetChecked(inputState->GetChecked());
+            DoSetChecked(inputState->GetChecked(), PR_TRUE, PR_TRUE);
           }
           break;
         }
diff --git a/content/html/content/src/nsHTMLInputElement.h b/content/html/content/src/nsHTMLInputElement.h
index 64c2699bfd25..94b1ed90f0dd 100644
--- a/content/html/content/src/nsHTMLInputElement.h
+++ b/content/html/content/src/nsHTMLInputElement.h
@@ -280,7 +280,7 @@ protected:
    * Do all the work that |SetChecked| does (radio button handling, etc.), but
    * take an |aNotify| parameter.
    */
-  nsresult DoSetChecked(PRBool aValue, PRBool aNotify = PR_TRUE);
+  nsresult DoSetChecked(PRBool aValue, PRBool aNotify, PRBool aSetValueChanged);
 
   /**
    * Do all the work that |SetCheckedChanged| does (radio button handling,