I suspect the cause of this is that the MPEG decoder in the mini-preview eats up the Xv port, then the MPEG decoder for the full-screen preview can't get the Xv port (it is in use) and falls back to non-Xv, and hence no hardware scaling.
Start an electricsheep on the command line, then invoke the screensaver (e.g., with xscreensaver-command -activate), and you'll see the same thing. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]