Running lxde and lxpanel on Debian 8.1. xdotool key XF86LogGrabInfo lists no actively grabbed devices in /var/log/Xorg.0.log. Clicking the Screenlock icon in the application launch bar has a long delay before activating screenlock and fails to grab the mouse, with the error couldn't grab pointer (AlreadyGrabbed). It fails to detect mouse movement to wake up the screensaver and doesn't intercept mouse events. The command xscreensaver-command -lock works properly so I've tried the following:  /etc/xdg/lxpanel/LXDE/panels/panel shows:Plugin {    type = launchbar    Config {        Button {            id=lxde-screenlock.desktop        }        Button {            id=lxde-logout.desktop        }    }}/usr/share/applications/lxde-screenlock.desktop shows it is executing lxlock:[Desktop Entry]Type=ApplicationName=ScreenLockName[es]=Bloqueo de pantallaName[pt_BR]=Bloquear telaName[ru]= Name[tr]=ScreenLockName[uk]= Name[zh_TW]=Comment=Lock your screenComment[es]=Bloquear pantallaComment[pt_BR]=Bloqueie sua telaComment[ru]= Comment[tr]=Ekran kilitleComment[uk]= Icon=system-lock-screenExec=lxlockTryExec=lxlockNoDisplay=trueEdited lxde-screenlock.desktop to execute xscreensaver-command --lock instead of lxlock:Exec=/usr/bin/xscreensaver-command -lockTryExec=/usr/bin/xscreensaver-commandEven though I've changed the desktop entry file and the lxsession configuration's lockscreen manager to xscreensaver-command -lock it lags and fails to grab the mouse when using the tray icon. I've restarted the lxsession and confirmed that this desktop entry is being used by the tray icon.Update:I've also tried adding the Lock Screen (XScreenSaver) menu item from the Debian section of the application menu to lxpanel's application launchbar. The problem persists. Screen lock functions properly when run by any other method (terminal, application menu, and LXDE logout menu), so I am inclined to call it a bug caused by lxpanel.Edit: I'm currently using an openbox keybinding to execute xscreensaver-command -lock as a work around, but I would still like to determine why running it from the application launcher fails.
xscreensaver screenlock Couldn't Grab Pointer - Already Grabbed
lxde;screen lock;xscreensaver