System Information
Windows 10, NVidia GeForce GTX 765M

Blender Version
Broken: (example: 2.69.7 4b206af, see splash screen)
Worked: (optional)

Short description of error

After an inset the normals of the surface start acting weird, having shadows where it's not suposed to.

This only happens when insetingn though, and when creating geometry with extrude or any other tool this doesn't happen:

Further more, I can clean the results and make the shadows disappear by removing the edges that hold the faces in the region together and recreating the faces, like this:

But new face is in contact with one "broken" face when created it gives even wronger looking results

Haven't been able to reproduce it in any other project so I don't know if its a proper bug or something I've done through the modeling processing.

Exact steps for others to reproduce the error

1. Selecting at least three faces

2. Inseting them