"Cinema Desktop Mode" broken

Did anyone try to put out a video with the Cinema Desktop Preview Mode? It seems to be broken on my macpro since "Snow Leopard". I use two ATI Radeon HD 2600 XT PCI Cards. In Cinema Desktop Mode the movie should be on the second Monitor of the first Radeon Card in fullscreen. Now the movie window pops up on the screen. Both, in Logic 8 and in Logic 9