terminator: reproducable
gnome-terminal: reproducable
xterm: not reproducable
konsole: not reproducable
I also noticed that the location of the mouse pointer matters when you switch from terminator/gnome-terminal to gedit: the mouse pointer should not be over the terminal window. If the mouse pointer is eg over a panel, the effect will occur, if the mouse pointer was over the terminal and you alt-tab into the gedit windows, it won't work.
terminator: reproducable
gnome-terminal: reproducable
xterm: not reproducable
konsole: not reproducable
I also noticed that the location of the mouse pointer matters when you switch from terminator/ gnome-terminal to gedit: the mouse pointer should not be over the terminal window. If the mouse pointer is eg over a panel, the effect will occur, if the mouse pointer was over the terminal and you alt-tab into the gedit windows, it won't work.