Rebuilt starter but still grinding - any other causes?

[patssle]

I had my starter rebuilt by a reputable local place - it worked fine for 2 weeks and now I have something grinding/screeching again for about 1 second on start-up. It sounds like the starter again. However the grind does sound different from when it was grinding before the rebuild. I put in a new ignition switch too just for the heck of it. It does not do it every single start-up. Is there anything else that can sound like a starter grind? Here is an audio file of the grind/screech if it helps.

www.patssle.com/grind.mp3