I have this problem in Ubuntu 14.04 and 16.04 with a dual 4K screen setup (using a nvidia GPU).
Sometimes when waking the screens from standby ("Power Save Mode"), windows on the right screen are moved to an invisible offscreen area. Using keyboard shortcuts, they can be moved to the visible area again. I just ran my screens through ~10 standby cycles in different configurations. One screen (Dell) wakes from standby almost immediately - the other (Iiyama) needs around 3 seconds. For simplicity, I will refer to them as quick and slow screen. Both screens are connected via DisplayPort. The driver from Ubuntu's nvidia-361 package is used. I made the following observations: * Window displacement happens on the right screen only. * When the quick screen is the right screen, you can see the windows at the correct positions after wakeup, then the slow screen wakes up, reinitialization seems to be triggered (both screens are black for one second) and after that the windows are displaced (sometimes). * When the quick screen is the right screen, random displacement seems to happen only once per Unity Session (if I logged out and in again, it happened again). When the slow screen is the right screen, it happens more often. * When window displacement occurs, windows seem to be swapped between the right screen and the invisible offscreen area (-> windows still in the invisible offscreen area reappear at their former positions). * Swapping the DisplayPort connectors at the Graphics Adapter does not have an impact on the behaviour. * KDE also displaces windows on wakeup. They are moved to screen edges instead of invisible offscreen areas. --- I am using the tint2 taskbar (window displacement also occurs without tint2). Its command line output at screen wakeup might be interesting. There are two variants of output (see below). Window displacement may occur on either. If displacement occurs, tint2 and also the menus in the title bar are often broken on one screen - until I restart tint2. First variant: /build/tint2-6JO0z5/tint2-0.12.7/src/tint.c 1163: triggering tint2 restart due to configuration change in the root window /build/tint2-6JO0z5/tint2-0.12.7/src/tint.c 1883: restarting tint2... xRandr: Found crtc's: 3 xRandr: Linking output DP-2 with crtc 0 xRandr: Linking output DP-4 with crtc 1 xsettings: Gtk/FontName = Ubuntu 11 xsettings: Net/IconThemeName = ubuntu-mono-dark real transparency on... depth: 32 panel items: TSC Systray composited rendering on tint2 : nb monitor 2, nb monitor used 2, nb desktop 1 Kernel uevent interface initialized... Second variant: /build/tint2-6JO0z5/tint2-0.12.7/src/tint.c 1163: triggering tint2 restart due to configuration change in the root window /build/tint2-6JO0z5/tint2-0.12.7/src/tint.c 1883: restarting tint2... xRandr: Found crtc's: 3 xRandr: Linking output DP-2 with crtc 0 xsettings: Gtk/FontName = Ubuntu 11 xsettings: Net/IconThemeName = ubuntu-mono-dark real transparency on... depth: 32 panel items: TSC Systray composited rendering on tint2 : nb monitor 1, nb monitor used 1, nb desktop 2 Kernel uevent interface initialized... tint2 : another systray is running pid=1908 /build/tint2-6JO0z5/tint2-0.12.7/src/tint.c 1163: triggering tint2 restart due to configuration change in the root window /build/tint2-6JO0z5/tint2-0.12.7/src/tint.c 1883: restarting tint2... xRandr: Found crtc's: 3 xRandr: Linking output DP-2 with crtc 0 xRandr: Linking output DP-4 with crtc 1 xsettings: Gtk/FontName = Ubuntu 11 xsettings: Net/IconThemeName = ubuntu-mono-dark real transparency on... depth: 32 panel items: TSC Systray composited rendering on tint2 : nb monitor 2, nb monitor used 2, nb desktop 2 Kernel uevent interface initialized... -- You received this bug notification because you are a member of DX Packages, which is subscribed to compiz-plugins-main in Ubuntu. Matching subscriptions: dx-packages https://bugs.launchpad.net/bugs/1295267 Title: Windows change Monitor/Desktop after screen lock Status in Unity: Fix Released Status in Unity 7.1 series: Fix Released Status in compiz-plugins-main package in Ubuntu: Confirmed Status in unity package in Ubuntu: Triaged Bug description: I run a dual monitor configuration, with one portrait and one landscape. I nearly always have multiple applications open in multiple windows across both monitors and all virtual desktops. When I lock the screen and then unlock, my application windows will move from their original position. Sometimes they are in completely random positions; Other times they seem to get the monitors confused, and rather than being in the top half of the portrait monitor they are on the top half of the landscape monitor; Sometimes it is only a new desktop, but the monitor position is the same; Sometimes it is the same desktop, but on the other monitor. Description: Ubuntu 13.10 Release: 13.10 What I expect to happen: When I unlock my computer, all the windows are in the same position on the same monitor and desktop as I left them. What actually happens: When I unlock my computer, some or all of the windows have been changed to a random position on a random monitor and/or desktop. To manage notifications about this bug go to: https://bugs.launchpad.net/unity/+bug/1295267/+subscriptions -- Mailing list: https://launchpad.net/~dx-packages Post to : dx-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~dx-packages More help : https://help.launchpad.net/ListHelp