Recently I found a weird problem with QTMovieView IB Plug-In on Snow Leopard.
If you create an XIB or NIB file on a Snow Leopard and add a QTMovieView to a Window, its movie controller is not displayed even though you check “Show controller” check box.
As you can see, they are exactly same as far as their nature is concerned. Also, whether it is XIB or NIB doesn’t matter.
ADDED : It doesn’t display the movie controller either with IB 3.1.4, the latest IB for Leopard.