As usual I didn't provide enough information.
This is a n-tier application where the OA ORM is running on IIs 7 on Windows Server 2008R2.
The production environment has much better hardware so it has to be configuration or SQL connection.
There is one thing I noticed that might be relevant and that is that the development IIs machine has SQLserver 2008 Native client installed where as the production doesn't have any SQLserver Native client installed.
The OA Orm product page says : "Telerik OpenAccess ORM provides built-in support for a wide range of databases to allow you to connect to one or more databases without the need to install additional components. "
Which I take as no need to install additional drivers.