Problem when using knife tool in Blender 2.65.

Hello, I’m new to Blender.
Sorry for my bad English. I hope you can understand me.
I’m following 608-Bearing modeling tutorials(in rab3D site by Robert Burke).
The tutorial is written for Blender 2.49. I’m using Blender 2.65.

The problem is like below. (1.68 MB)

I tried switching off the midpoint snap and clicking that vertex, but I cannot click precise position.
What should I do?

I attached my working .blend filles.

If you make a face using that vertex or just position the knife curser over that point without it snapping


ah… making a face! Thank you very much!