Well, actually I should describe the behaviour in more detail, to make sure it is rigorously the same.
At first, everything seems normal. When the world map has been rotating for a while, it turns white. Something similar happens to most of the textures, which gradually disappear. This includes images in the ufopedia, parts of the base display, and in-mission textures. I can actually get the missions to run, only with a varying number of missing textures. Another error that I have noticed recently is that units sonteimes get textured with bits of white-on-black text, which gives a pretty funny effect.