[arch-general] lxde setting problems

1. Pressing the printscreen button opens an openbox dialog that says it couldn't execute gnome-screenshot. I don't use gnome and I don't want printscreen to do anything. 2. I use lxde and I like my task bar at the top of the screen. There is always a pixel above the open tasks so I can't just move the mouse to the top and select a task. I have to click on the task name (which is difficult for me). I tried setting the margin to 0 in the panel settings and setting the spacing to 0 in the taskbar settings. 3. Windows open (and can be moved) so the part of the window that can be dragged can be under the taskbar (I have autohide set to off).