.Net客户端使用错误的提供程序连接到SQL 2005

I am trying to connect to a database on a server from a developer machine. The server has the named pipes protocol disabled. For some reason from one developer's box we get the following error message. Two other developer boxes can connect using the same code just fine (using tcp/ip). I have tried disabling The named pipes protocol on the client and still receive the following message.I am trying to connect to a database on a serve