A bug*, is this a bug…Dammit… XD Can’t edit the title. Anywho…
I accidentally used the mask brush in this mode (I was doing some clone stamp painting just before this) instead of sculpt mode but for some reason around when I did all this textured view went…funny… Wireframe mode shows an inverted texture and bounding box shows the same thing. The other modes viewport shading views are fine. I’ve made this gif to show what I mean: http://i.imgur.com/tiXCLp8.gif
I’m using blender 2.76 and this is the only texture in the scene, also GLSL mode looks fine in textured view but not the other views (in texture paint mode). On top of this clone stamp doesn’t work now (although I do wonder if I turned something off by mistake whilst mucking around trying to get the correct texture view back) :o I’ve also found that if I invert the texture in the UV editor it shows up correctly in wireframe/bounding box view.
EDIT: I’ve just done the obvious thing now of appending my model into a new blend file, problem has disappeared