I think i have reported this before, but cannot find it anymore.
Sometimes when i test my project and close the running level the views in the WED looses the textures. It displays in solid, non textured then. Pressing F7 helps nothing, nor does recreating views. I have to end and to restart WED to get my textured view back.
I cannot really say what causes it. Sometimes it doesn't show for several sessions, and then it comes back.