When aspnet_regsql.exe was run it would have written a bunch of tables and sprocs to the db at the connection string specified at the time. If the database has moved you now need to modify that connection string so it points to the new production server.

Open net.config and look for a connection string that looks like <add name="LocalSqlServer" connectionString="Server= .....

I know it's counterintuitive to have something pointing to "LocalSwlServer>; the reference is to the database your application is running on, not to your development machine. You may confirm this by examining the rest of the string ... the i.p. should point to the production server. You need to change this connection string so it points to you production server.

Directly _above_ that connection string you should add <remove name="LocalSqlServer"/>

Next look for <membership defaultProvider="AspNetSqlMembershipProvider" .... In that line there should be a parameter "Appplication name ...." the default value is "/"/. If yours is et to "/" I suggest you change it to something meaningful, you'll understand in a moment. This _may_ not required to make application work. You can review the article at this link to understand the significance of application name: http://weblogs.asp.net/scottgu/archive/2006/04/22/Always-set-the-_2200_applicationName_2200_-property-when-configuring-ASP.NET-2.0-Membership-and-other-Providers.aspx

You should next look at the actual database and find this table: aspnet_Applications. You need to add or update the ApplicationName value to match the one you entered in the <membership defaultProvider ... parameter.

You can now test this by opening the web configuration too in VS2005: Website/ASP.NET configuration and confirming that the Security tab works.

All the above is relevant my particular setup on a remote SQLServer instance. It may or may not be relevant to your setup. Good luck.