BLOCK SCALE

Does anyone can help me?

When I insert an xref it's to scale 12!; in my model space I have blocks scaled 0.0833 and others to 1 scale! this is weird, every time I insert a block I need to scaled it in the way to adjust it to my drawing. If my drawing it's supposed to be 1 scale, why am I having this problems?

Thanks,

JL