slow with material

[Jarek Rzepecki <jarekr@xxxxxxxx>]

Hello!
    I need to draw a lot of lines (SoLineSet). When I'm drawing those
lines without adding material - that is I'm drawing them in default color
etc... it is fast. But when I try to draw those lines with materials the
whole thing  is getting much slower... Why is that?
(by material in this case I mean only diffuse color)
Cheers,
        Jarek