I use XMonad+gnome as window Manager. I have the problem that, when I run a Java Web Start applicacion, It olways show an empty window, like the screen:

Is there something I can do to fix it?
UPDATE:
I tried simple programs from JWS Examples and it works, right. So it should be a problem of the application.
The failed aaplication is Blast2Go.
Change the name of the window manager to a known one like
LG3D: