--- a/content/base/src/nsObjectLoadingContent.cpp
+++ b/content/base/src/nsObjectLoadingContent.cpp
@@ -129,24 +129,24 @@ nsAsyncInstantiateEvent::Run()
   mContent->mPendingInstantiateEvent = nsnull;
 
   // Make sure that we still have the right frame (NOTE: we don't need to check
   // the type here - GetExistingFrame() only returns object frames, and that
   // means we're a plugin)
   // Also make sure that we still refer to the same data.
   nsIObjectFrame* frame = mContent->
     GetExistingFrame(nsObjectLoadingContent::eFlushContent);
-#ifdef DEBUG
-  if (frame && mFrame.IsAlive()) {
-    nsIFrame* objectFrame = do_QueryFrame(frame);
-    NS_ASSERTION(objectFrame == mFrame.GetFrame(), "Wrong frame!");
+
+  nsIFrame* objectFrame = nsnull;
+  if (frame) {
+    objectFrame = do_QueryFrame(frame);
   }
-#endif
-  if (frame &&
-      mFrame.IsAlive() &&
+
+  if (objectFrame &&
+      mFrame.GetFrame() == objectFrame &&
       mContent->mURI == mURI &&
       mContent->mContentType.Equals(mContentType)) {
     if (LOG_ENABLED()) {
       nsCAutoString spec;
       if (mURI) {
         mURI->GetSpec(spec);
       }
       LOG(("OBJLC [%p]: Handling Instantiate event: Type=<%s> URI=%p<%s>\n",