Win7 64 bit, 16 GB RAM, an AMD 7xxx GPU, third gen i7 processor
Broken: Blender hash 5693337
Short description of error
On some meshes, the connect tool (J-Key) will fail to make a straight cut between two vertices and might even cut across the back of the mesh rather than what's visible to the user.
Exact steps for others to reproduce the error
Open the .blend file and press 'J'