diff --git a/browser/base/content/nsContextMenu.js b/browser/base/content/nsContextMenu.js
index 3cb6ea92ec33..23db1da07b58 100644
--- a/browser/base/content/nsContextMenu.js
+++ b/browser/base/content/nsContextMenu.js
@@ -807,7 +807,7 @@ nsContextMenu.prototype = {
     this.target.pause();
 
     openDialog("chrome://browser/content/fullscreen-video.xhtml",
-               "", "chrome,dialog=no", this.target);
+               "", "chrome,centerscreen,dialog=no", this.target);
   },
 
   // Change current window to the URL of the background image.
diff --git a/xpfe/appshell/src/nsWebShellWindow.cpp b/xpfe/appshell/src/nsWebShellWindow.cpp
index 9c5af97ac1a8..1f877e05d414 100644
--- a/xpfe/appshell/src/nsWebShellWindow.cpp
+++ b/xpfe/appshell/src/nsWebShellWindow.cpp
@@ -175,7 +175,7 @@ nsresult nsWebShellWindow::Initialize(nsIXULWindow* aParent,
 
   // XXX: need to get the default window size from prefs...
   // Doesn't come from prefs... will come from CSS/XUL/RDF
-  nsIntRect r(0, 0, aInitialWidth, aInitialHeight);
+  nsIntRect r(mOpenerScreenRect.x, mOpenerScreenRect.y, aInitialWidth, aInitialHeight);
   
   // Create top level window
   mWindow = do_CreateInstance(kWindowCID, &rv);