Admin on dev site redirects to Live site

I have 2 wordpress sites set up. Each is set up twice – once in my development location, and once in my live location. For one of them,

http://www.hridev.com/atlast2010/

When I go to log in, it works fine, keeping me at http://www.hridev.com

But, the other:

http://www.hridev.com/2012nssme/

When I add wp-admin to the end, it takes me to the log in for my live site:

http://www.horizon-research.com/2012nssme/

I don’t see anything suspicious in either the .htaccess file, or the wp-config file.

Any advise on where I should look and what I should look for?

Please and thank you,
Alison