i am using two screens, yes. i just installed and activated metacity .. after reboot (due to crash after activating metacity) the desktop has mostly reset and some functions do not work as they should. the cairo-dock hiding issue remains and the dock does not unhide. i then reactivated marco using marco --replace and saw: Window manager warning: Missing composite extension required for compositingglibtop: Non-standard uts for running kernel: release 3.10-2-amd64=3.10.0 gives version code 199168 i have now uninstalled metacity and marco is loaded again ok. 'use compositing' is enabled in the os settings. if i disable 'fake compositing' in cairo-dock settings then the black bar appears with the cairo-dock. i am fairly sure that cairo-dock did load ok initially, was hiding ok and was composited correctly without 'fake compositing' after initial install... possibly the nvidia driver was changed during the update pack 7 installation of lmde. On 01/10/13 09:56, Fabounet wrote: > Hi, > do you have some special configuration, like a double screen ? > or maybe the fake transparency is activated (you can check it in the > advanced configuration -> "System" tab) > > can you try with another Window Manager, like Metacity (you may need to > install it, and then type "metacity --replace&" > > > 2013/9/30 ura soul