Hiding LinuxMCE windows from KDE desktop
From LinuxMCE
By default, there are 3 LinuxMCE windows from desktop #5 displayed in taskbar even when you are on desktops 1-4. You can adjust the settings to not display them in task bar (and avoid occasional clicking on them): right click on the task bar, then "Configure Panel => Taskbar => unmark tick 'Show windows from all desktops'".