Database Mirroring. Asp Application (IIS 6.0) Does't Forward Connections To Mirror Server

Hi!

I have setup a database mirroring session without witness - ServerA is the principal, ServerB is the mirror,. Each SQL Server instance is hosted on its own machine on sql2005 EE SP2. The mirroring is working correctly. If I submit to server ServerA command:

ALTER DATABASE MYDBNAME SET PARTNER FAILOVER

, ServerB becomes the principal, it means that mirroring works correctly.

My issue is with the SQL Native Client and a front-end ASP application (actually IIS 6.0 site) that needs to make use of this database. I have setup my front-end application to use SQL Native Client and specified the failover server in connection string. Here is the connection string that I am using :

PROVIDER=SQLNCLI.1;Server=ServerA,1433;Failover Partner=ServerB,1433;Database=MYDBNAME;Network=dbmssocn;Integrated Security=SSPI;

Everything works perfectly on my front-end application when ServerA is the principal. If I execute on server ServerA command:

ALTER DATABASE MYDBNAME SET PARTNER FAILOVER

, ServerB becomes the principal, and the failover occurs correctly on the database side. The problem is that my front-end application is not able to query the database on ServerB. The error appears:

Microsoft SQL Native Client error '80004005'

Cannot open database "MYDBNAME" requested by the login. The login failed.

This behavior my appication till I unload IIS 6.0 pool application. After that my front-end application becomes work correctly with ServerB.

When I swap server, I execute on server ServerB command:

ALTER DATABASE MYDBNAME SET PARTNER FAILOVER,

my IIS 6.0 application automaticly turn back to ServerA without any action on my side.

I am using SQL Native Client last version http://download.microsoft.com/download/2/7/c/27c60d49-6dbe-423e-9a9e-1c873f269484/sqlncli.msi (issued in February 2007). Has anyone experienced this issue? I'm thinking that it's a problem in the SQL Native client