I downloaded this http://www.thingiverse.com/thing:489323 and saw there were some issues with the drawing. Things didn't line up perfectly, so I redrew it. The old version has some errors that are autofixed (you can see them on the thing view of the original STL) in slic3r. My version should not have any errors when importing into your slicing software.

http://westrealm.com/category/3d-printing/