how are you texturing? Are you using the uv window settings or are you using a different method? I know when I first started with blender, I avoided the uv window because it was "too hard to understand", and used the texture button instead. Now I am expertimenting with uv, and sometimes the textured view does just as you describe. I figured it's my poor 'puter, since this one was not put togther to handle 3d rendering very well. It barely handles 2d images as it is.