I can't texture paint with the wireframe lines visible. The only way I can see the lines is if none of the mesh is selected - but then I can't paint...
I have the exact same problem. It looks like a bug to me but im not sure about this.
Anyways, Go to your Object Properties in the Main Pannel on the right. In the Display options activate "Wire". That way you can see the wireframe of your mesh also when all verts are selected.