Admin Account Locked Out - Any Ideas?

[andoverit]

Issue is as follows:

1) Site was built using Corporate theme at http://www.ourdomain.com/clientname
2) On going live we created http://www.clientname.com and moved files over then restored backup
3) Logged in as admin at http://www.clientname.com and all looked okay
4) Went to Settings > General (using WP v2.7.1) and amended Wordpress and Blog address from http://www.ourdomain/clientname to http://www.clientname.com
5) As soon as saved we were immediately logged out

Tried logging back in at http://www.clientname.com/wp-admin however it redirects to http://www.ourdomain.com/clientname/wp-login.php

If we request a new password is says "Sorry, that key does not appear to be valid."

Any suggestions greatly received.