Multiple Domains

I originally owned the domain www.clangc.net. I started to make a texas holdem related site using the domain. I later decided to go through with the website and purchased www.holdemcrew.com. The site has been up for about a month and a half, and things seem to be going well (I have changed the website to be more of a business now). I still use clangc.net as a backup/testing server. I make most of my changes there before I make them live on holdemcrew.com.

My concern is that I now have 2 webpages with the exact same content indexed in the search engines (With one linking to the other..). I think I read somewhere that that is a major no-no. In most engines, if you search holdem crew or holdemcrew, the clangc.net version actually ranks higher than the holdemcrew.com one. Is this a problem? Can I take the clangc.net listins out of the search engines? Can I just tell them not to spider my site anymore with robot.txt?

Thx,

HoldemCrew

Likely one of the domains will get filtered if Google is spidering both of them. Maybe you should add robots no index tag to the old domain.