SDL_FillRect() does nothing in fullscreen on WinXP

I’ve just started playing with SDL (in preparation for a final year
project for a Computer Science BSc) and it’s great. I made a quick app of
some floating objects, using SDL_FillRect to fill the screen with a color at
the start of each loop, then drawing the rest on top, like this:

SDL_FillRect(screen, NULL, 0xCCCCCC);

This works great in a window, but if I change the SDL_setVideoMode call

to make it fullscreen, it’s as if SDL_FillRect is totally ignored; the
background is black and the objects on top leave trails as the background
isn’t being rewritten. I’m using Windows XP and Visual C++ 6; I guess it
might be something to do with DirectX being used in fullscreen? Or maybe
something with the screen buffers pointing the wrong way. I don’t know
really, that’s why I’m asking :slight_smile:

Nick H