GTK+ Window hack

Hello,

I want to use SDL with GTK+, and I found the window hack. I have been
able to get it to work, but the question I have is: is it possible to
have multiple windows open? (with each window having an SDL surface.)
Currently it seems that two applications running at the same time, both
using the SDL window hack, will cause a conflict. Am I correct in
thinking this? If this is a known problem, are there any plans to
correct this?

Thanks,
Erik

P.s. For your reference the window hack code looks something like this
(with window_id being the id of the GTK+ window):

gchar SDL_windowhack[32];

sprintf (SDL_windowhack,“SDL_WINDOWID=%ld”, window_id);
putenv (SDL_windowhack);