Hi, Thanks, but I still have another problem !!! I have 2 dockwidgets in my qmainwindow: qtosg and vlc-qt. when I play movie in the second dockwidget, the first one(QT&tOSG) becomes black! :( Cheers, Wojtek ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=66486#66486