.NET 2.0 COM Excel add-in stops responding when SqlConnection object is created

Dear All

I have encountered a problem when creating a
System.Data.SqlClient.SqlConnection in my Excel add-in.

I am using:
- Visual Studio 2005
- Excel 2003 SP2

I created the add-in with the VS2005 Shared Add-in Wizard. I then included
the required Office and Microsoft.Office.Interop.Excel assembly references.

In the OnConnection method I add two buttons to the Excel menu. In the first
button (called createSqlConnectionButton) I do the following:
System.Data.SqlClient.SqlConnection conn = new
System.Data.SqlClient.SqlConnection();

In the second button (called createOleDbConnectionButton) I do the
following:
System.Data.OleDb.OleDbConnection conn = new
System.Data.OleDb.OleDbConnection();

I attach the code to this post.

When I press the createOleDbConnectionButton to execute its event handler,
everything works fine.

When I press the createSqlConnectionButton to execute its event handler, it
also executes, but after that, the add-in does not respond to any user
interaction from these buttons any more.

Any help on this will be greatly appreciated.

Kind regards

Johan Zietsman