Troublesome background of Text widget

[Preben Randhol <randhol pvv org>]

I'm trying to change the background of a Text widget from white to a
darker color. At the moment I'm trying with black. I first get the style
from the Text widget, then I set the background of the Normal state to
the black color and finally I apply the style on the Text widget again.
The problem is that the white background remains and I get some sort of
"black border" around it.

I have looked in both "Developing Linux Applications with GTK+ and GDK"
and "GTK+/Gnome Application Development" without luck.

Ada 95 Source Code:
   [...]

   Gtk_New (Window1.Text2);
   Pack_Start (Window1.Vbox2, Window1.Text2, False, False, 0);
   Set_Editable (Window1.Text2, True);
   Set_Sensitive (Window1.Text2, True);
   Window1.Style := Get_Style (Window1.Text2);

   Set_Rgb (Black_Col, 0, 0, 0);

   Set_Background(Window1.Style, State_Normal, Black_Col);
   Set_Style (Window1.Text2, Window1.Style);

   [...]

-- 
Preben Randhol -- [randhol@pvv.org] -- <http://www.pvv.org/~randhol/>
         "Det eneste trygge stedet i verden er inne i en fortelling."
                                                      -- Athol Fugard