Moving .mdf from development to server for forms authentication

Hi all,
I'm finishing up my first ASP.NET application (in C#). I've used  Visual Web Developer 2008 Express Edition to build it. One page requires logging in - I was able to configure a LoginForm that worked properly on my local machine. Authentication was configured in the web configuration interface. From my understanding, this creates the SQL Express database ASPNETDB.MDF in App_Data.
The rest of my code was moved successfully from development to the production server. All the pages (including those that hit SQL Server 2005 databases) are working correctly but I get the following error when authenticating:

An error has occurred while establishing a connection to the server.  When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified ...