Back to window-mode from fullscreen failed.

Debian 2.6.32-5-amd64
jogl-2.0-pre-20101108-linux-amd64
NVIDIA 195.36.31

I'm using a GLWindow from NEWT.
I use the glWindow.setFullscreen(true) to go to fullscreen mode. This works fine.
When I try to go back to window-mode with the same method, the window blinds and return to fullscreen mode.

Is there something to do more than  glWindow.setFullscreen(boolean) ?

Thanks.