diff --git a/layout/xul/base/public/nsXULPopupManager.h b/layout/xul/base/public/nsXULPopupManager.h
index 6d70045142f5..e87eee6e38d4 100644
--- a/layout/xul/base/public/nsXULPopupManager.h
+++ b/layout/xul/base/public/nsXULPopupManager.h
@@ -337,8 +337,11 @@ public:
   static nsXULPopupManager* GetInstance();
 
   // get the frame for a content node aContent if the frame's type
-  // matches aFrameType. Otherwise, return null.
-  nsIFrame* GetFrameOfTypeForContent(nsIContent* aContent, nsIAtom* aFrameType);
+  // matches aFrameType. Otherwise, return null. If aShouldFlush is true,
+  // then the frames are flushed before retrieving the frame.
+  nsIFrame* GetFrameOfTypeForContent(nsIContent* aContent,
+                                     nsIAtom* aFrameType,
+                                     PRBool aShouldFlush);
 
   // given a menu frame, find the prevous or next menu frame. If aPopup is
   // true then navigate a menupopup, from one item on the menu to the previous
diff --git a/layout/xul/base/src/nsXULPopupManager.cpp b/layout/xul/base/src/nsXULPopupManager.cpp
index 373c6dedc17e..c8c472cfb840 100644
--- a/layout/xul/base/src/nsXULPopupManager.cpp
+++ b/layout/xul/base/src/nsXULPopupManager.cpp
@@ -212,12 +212,16 @@ nsXULPopupManager::GetSubmenuWidgetChain(nsISupportsArray **_retval)
 
 nsIFrame*
 nsXULPopupManager::GetFrameOfTypeForContent(nsIContent* aContent,
-                                            nsIAtom* aFrameType)
+                                            nsIAtom* aFrameType,
+                                            PRBool aShouldFlush)
 {
   nsIDocument *document = aContent->GetCurrentDoc();
   if (document) {
-    nsIPresShell* presShell = document->GetPrimaryShell();
+    nsCOMPtr<nsIPresShell> presShell = document->GetPrimaryShell();
     if (presShell) {
+      if (aShouldFlush)
+        presShell->FlushPendingNotifications(Flush_Frames);
+
       nsIFrame* frame = presShell->GetPrimaryFrameFor(aContent);
       if (frame && frame->GetType() == aFrameType)
         return frame;
@@ -230,15 +234,16 @@ nsXULPopupManager::GetFrameOfTypeForContent(nsIContent* aContent,
 nsMenuFrame*
 nsXULPopupManager::GetMenuFrameForContent(nsIContent* aContent)
 {
+  // as ShowMenu is called from frames, don't flush to be safe.
   return static_cast<nsMenuFrame *>
-                    (GetFrameOfTypeForContent(aContent, nsGkAtoms::menuFrame));
+                    (GetFrameOfTypeForContent(aContent, nsGkAtoms::menuFrame, PR_FALSE));
 }
 
 nsMenuPopupFrame*
 nsXULPopupManager::GetPopupFrameForContent(nsIContent* aContent)
 {
   return static_cast<nsMenuPopupFrame *>
-                    (GetFrameOfTypeForContent(aContent, nsGkAtoms::menuPopupFrame));
+                    (GetFrameOfTypeForContent(aContent, nsGkAtoms::menuPopupFrame, PR_TRUE));
 }
 
 nsMenuChainItem*
diff --git a/toolkit/content/tests/widgets/Makefile.in b/toolkit/content/tests/widgets/Makefile.in
index 60a27a86de22..7ad628e93cdb 100644
--- a/toolkit/content/tests/widgets/Makefile.in
+++ b/toolkit/content/tests/widgets/Makefile.in
@@ -80,6 +80,7 @@ _TEST_FILES = 	test_bug360220.xul \
 		test_hiddenpaging.xul \
 		test_popup_tree.xul \
 		test_popup_keys.xul \
+		test_popuphidden.xul \
 		$(NULL)
 
 ifeq (,$(filter mac cocoa,$(MOZ_WIDGET_TOOLKIT)))
diff --git a/toolkit/content/tests/widgets/test_popuphidden.xul b/toolkit/content/tests/widgets/test_popuphidden.xul
new file mode 100644
index 000000000000..c8cd72b285d9
--- /dev/null
+++ b/toolkit/content/tests/widgets/test_popuphidden.xul
@@ -0,0 +1,42 @@
+<?xml version="1.0"?>
+<?xml-stylesheet href="chrome://global/skin" type="text/css"?>
+<?xml-stylesheet href="/tests/SimpleTest/test.css" type="text/css"?>
+
+<window title="Hidden Popup Test"
+  onload="setTimeout(runTests, 0);"
+  xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+
+  <script type="application/javascript" src="/MochiKit/packed.js"></script>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>      
+
+<menupopup id="popup" hidden="true" onpopupshown="ok(true, 'popupshown'); this.hidePopup()"
+                                    onpopuphidden="SimpleTest.finish()">
+  <menuitem id="i1" label="One"/>
+  <menuitem id="i2" label="Two"/>
+</menupopup>
+
+<script class="testbody" type="application/javascript">
+<![CDATA[
+
+SimpleTest.waitForExplicitFinish();
+
+function runTests()
+{
+  var popup = $("popup");
+  popup.hidden = false;
+  popup.openPopup(null, "after_start");
+}
+
+]]>
+</script>
+
+<body xmlns="http://www.w3.org/1999/xhtml">
+<p id="display">
+</p>
+<div id="content" style="display: none">
+</div>
+<pre id="test">
+</pre>
+</body>
+
+</window>