Solid Lines between 2 points changing changing colors

["Alfredo Macias" <alfredom@sbceo.org>]

Hi.
I have a problem and would appreciate any hints that would help me solve it.

I'm running my ada program on Linux 9. something.

This is the code I'm running:

Gl.Glbegin(Mode);

      for I in 1..2 loop
            Gl.Glvertex2d
                              (Gl.Gldouble(Data.Item(I).Coord1),
                               Gl.Gldouble(Data.Item(I).Coord2));
       end loop;

 Gl.Glend;

I only have two 2d points, so this code draws a thick line on the screen
between point1 and point2.
However, about 60 % of the line is of the right color, the rest of the line
is some times white and some times yellow.
This never occured when I was running the exact same code on AIX, only on
LINUX.

Is there a default setting that I could have set on my OpenGL installation
on LInux that I don't have on AIX?
As far as I can see, the two installations have the same default settings.
Any Hints?

Thank you very much