asp.net mvc - provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified No fix? -

I recently added another site to my server This site makes me dangerous:

System.Data.SqlClient.SqlException: A network-related or instance-specific error occurred when installing the connection to SQL Server, the server was not found or was not accessible. Verify that the example name is correct and SQL Server is configured to allow remote connection. (Provider: SQL Network Interface, Error: 26 - Server / Instance Specified Error)

I do not know why I'm getting this. I have gone through and have no use It is a new MVC4 application on beta.vinformative.com in IIS 7. The other site is a MVC3 site on vinformative.com. It's working fine both of them have exact same connection string in the database and they are on the same SQL Server. I have given the same membership in both databases for the same user mapping and NT Authority \ network service.

Microsoft SQL Server service is running with SQL Server Browser and SQL Server Agent

Port 1433 TCP added to firewall

Db sir Remote connection enabled on top

Successfully pinged machine

Portable used to view DB server on UDP 1434

I Besides the site locally when I am logging in to my server remotely, I have an ELMAH example in the application for error logging and it is updating the database correctly I think I am using crazy pills I'm taking this job because Hia and I did not get a full error. Please help!

This is my connection string

  & lt; Add name = "vfContext" connectionString = "data source = vinformative; initial catalog = vf3; integrated security = true" provider name = "System.Data.SqlClient" />    
 
 
 can be EF - Also, remote access "Integrated security = true" should be used as far as I know, "User ID = ******; Password = ****; Integrated Security = Incorrect".