Comment 11 for bug 1109812

@Christopher: The oxygen theme allows dragging on any empty area in a window to move it, and for some reason the rulers are being treated as empty areas (most likely an issue in a mouse event handler). As a workaround, you can specify that oxygen only allows window moving via title-bar drag by running "oxygen-settings" and changing the "Windows' drag mode" in the "General" tab of the "Widget Style" settings. Hope that helps!