Caching mirror sites

google is caching a backup copy of my site not the site

[comforteagle]

Ok, this is odd.

I have a few people running mirrors of my site example.com but adding local content.. so there's example.com & us.example.com & ca.example.com

The problem is that google is caching us.example.com not the parent example.com.

Suggestions other than killing off the mirror sites?