I have actually heard and know for a fact (my sister for example) of those having their tbes tied but then they come untied. I wonder if this is the fault of the doctor per say or it depends on the lady in question, if its possible something she does (or her body in general) just does not hold the tie as others would.

I think it is a great method of birth control. I have heard it does not hurt and you can be back up on your feet the same day or the next day. However, I have heard of people still getting pregnant in a few cases after getting their tubes tied.