[SDL] OpenGL in threads?

[Jan Klesnil]

Can SDL run with one thread for drawing in OpenGL, one thread for 
event-handling, one thread... ? I it can, what am I doing wrong?

main()
{

SDL_Init(SDL_INIT_VIDEO);
gfx = SDL_CreateThread (graphics_thread, NULL);

events = SDL_CreateThread (events_thread, NULL);

SDL_WaitThread(gfx, NULL);
SDL_WaitThread(events, NULL);
	
SDL_Quit ();
}

This program behaves very unpredictably...  Sometimes can't get input 
from keyboard, sometimes quits immediatly, sometimes crashes with 
SIGFAULT or hangs, sometimes doesn't open window, but never runs 
correctly...