Hello, I have debian 2.0 too. My window manager is WindowMaker. My scilab works well. I've compiled it myself. Have you tried to do that. Is really easy, once you have the development (gcc and g77) stuff installed.
The only problem I get is that the graphic window doesn't pop up when it is created by scilab. I must use the window list menu to make it appear. This seems to be a problem of window maker, since the graphic windows appears under fvwm2 and icewm. Hope that helps. Paulo.
