Another workaround is to hack the theme itself. For the Ambiance theme edit /usr/share/themes/Ambiance/metacity-1/metacity-theme-1.xml and in the section starting
<frame_geometry name="frame_geometry_normal"
change left_width, right_width and bottom_height from 1 to 3.
I have not tried it on the Radiance theme but I expect the same change would work there. Keep a note of what you have done as if the theme is updated you might have to do it again.
Another workaround is to hack the theme itself. For the Ambiance theme edit /usr/share/ themes/ Ambiance/ metacity- 1/metacity- theme-1. xml and in the section starting geometry_ normal"
<frame_geometry name="frame_
change left_width, right_width and bottom_height from 1 to 3.
I have not tried it on the Radiance theme but I expect the same change would work there. Keep a note of what you have done as if the theme is updated you might have to do it again.