I really liked the design of this cable clip by magicxman but was unable to get it to print. Slic3r had errors with it, I put it through netfab to fix them but the sides would only print about 50%.
So I imported the file to sketchup and pretty much redid it making the sides thicker. I'm not sure what software it was created in but it wasn't a solid shape, but now it is. Other people have printed magicman's version so it must be ok for some setups, just not for mine.
Now Slic3r can handle it and it prints fine on my Prusa Mendal. So if you're having issues with the other file, try this one.