alpha-blending with visad-in-a-box

Hi Everyone,

        I'm heading off to Vienna today to demo my application. Only one 
problem:
the alpha-blending that works so well on my desktop doesn't work on my
laptop. I've installed visad-in-a-box, and the 3D plots work fine, but the
alpha just doesn't happen (the plot is there, but it is not transparent!).
Is this an OpenGL issue? (I read somewhere that visad-in-a-box uses OpenGL).
I've spent the better part of 3 days on this, so at this point I'm looking
for any suggestions at all!

        Thanks for your time,

        Adele