ASP.NET membership and SQL Server 2008 connection problem

I'm using ASP.Net Membership, IIS 7 and SQL Server 2008.

I can connect to all the tables in 开发者_如何学Pythonthe remote SQL Server except the Membership ones.

I get this error:

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

• I can connect fine when I click Website\ASP Configuration from Visual Studio, which is using the exact same connection string.
• Others in the office using the exact same code they connect from their IIS.
• The exact same code works fine if I change the connection string to point to a SQL Server 2005 database.

It is something weird I can't figure out. Any help will be greatly appreciated.

By the way I read ASP.Net membership + sql server 2008, but I already use SQL authentication.