Testgl problem or bug?

i just manage to build fine ParaGUI and its tests on my computer
i have windows 2000, SDL_1.2.1, mingw_1.0, ParaGUI_0.7.1

The widget demo (paratest.cpp) works fine.

but, when i run testgl (ParaGUI OpenGL test program) in full screen mode
i have a strange behavior.

the screen is mixed with tesgl and my desktop, i mean that i constantly
get my desktop to appear and be overlapped with test gl drawing as in
non double buffered program though, i guess, the desktop is not part of
my window !

and, second, the widget are not where they seem, i mean for input
(mouse) event to work i have to click outside widget.

what does this 2 weird things mean ?