Hello, I don't have this bug anymore. I don't know why but this is the changes I made before he disapeared: 1°) I'm using no more Baghira style for KDE (I prefer Kore, very nice!!!) 2°) I entirely desinstall beryl git 3.0 and all his dependencies 3°) I installed compiz-fusion Voilà. Thanks for your attention. LGDN