Textures going south on winxp

whenever I minimise my opengl/SDL app (1.2.11), both in windowed and
fullscreen mode,
then bring it back to the fore, the textures get all screwed up. I’ve
heard you’re supposed
reinit video on a resize event and hence reload textures, but I’m not
getting a resize event,
I’m getting an SDL_ActiveEvent with the SDL_APPACTIVE state flag set. Should
I be doing the same in this latter case? This doesn’t seem to be
necessary in the
mac version.