Problem drupal with domain and redirection
The problem could be in several areas, depending on your deployment method.

First of all, have you cleared your caches?  This fixes most issues, especially after importing a database.

It could be a server configuration issue, did you set it up or did someone else?  There could be version differences between the installed software on the dev and prod servers.

Lastly, have you tried setting the $base_url in your settings.php?