Texture paint won't work with Alt+B (view clipping border) activated

Hi all,

I am trying to texture paint using a clone brush (painting from one UV to another), which works fine, except when I try to hides parts of the model using Alt+B(view clipping border). When I do this, texture painting from the clone brush doesn’t work at all. When I try to open random files to test painting while in Alt+B mode, sometimes it works and sometimes it doesn’t and I have no idea why! I know it is supposed to work…I have seen it done in tutorials. Texture painting has been difficult in Blender in general, because it will work sometimes and not other times–very frustrating.

Here is my blend file: http://www.mediafire.com/?395w9498zd71ao4