I am having an issue with mating, hopefully its just a feature that is on that I do not like. Hopefully I can say this right.

I have an assembly and all the components are in their correct spots but are not fully defined by mates. I have 2 plates with holes in them, the holes are concentric but there is no mate saying they are concentric, I add a concentric mate to those parts and it concentric them but moves the part a certain distance away which in turn moves all my components that are referenced to that part causing a ton of problems. I use to be able to just add the dimensions and the parts wouldn't move on my. It is not limited to a certain type of mate.

1, 2 & 3 are all on the same plane. No mates are present.

I mated 2 & 3 no problem, I mate 1 & 2 and the parts shift.