We are moving to a new server and the first of our DNN sites that we migrated is having a login issue.  The site works fine on the test domain (we haven't made the final move yet), but we are not able to login as any user.  The homepage and all modules work, we have the database and sites file in place and the SQL connection strings updated.  When we try to login on the new server, we get an error that login failed.  However, the same credentials work on the old server.  The only thing I can think of that would cause this is the machine key, but we are using the same web.config, so that is also the same.  Where should we work, or what could possibly be going wrong that is causing logins to fail?  Thanks for your help and assistance.