Deploying to Production user login

I have just deployed our App to the Production environment for the first time. Although I can login as Administrator none of the users with privilleges less than Administaror can log in. Can you think of any thing I have forgotten? They can all logon to the Acceptance Test environment without a problem. Many thanks Ray
1 answers

I have now resolved this. I did not have 'User' selected as well as their business role.