Connection failed to SQL server 2008 from ADP access 2007.

ADP Microsoft access 2007.
I be able to connect to server SQL 2003 without a problem.
OBDC connection to SQL Server 2008 without a problem.
Logon to SQL Server 2008 without a problem.
On my local pc does have Microsoft SQL Server 2008 driver installed.

But when connect to server SQL server 2008 through test connection.
I have the following error:

On the Data Link Properties:
Connection tab;
1. Select or enter a server name: (I click on the drop
down arrow and select the server name.
2. Use Windows NT Integrated security (I select this)
Click on the Test Connection button and the following error box display:

Test connection failed because of an error in intializing provider.
[DBNETLIB][ConnectionOpen (Invalid Instance()).]Invalid connection.

Any help is appreciated :)
Thanks, nghiem