I created a testapp with the code below. But when switching to design mode
of the test form, I get the following message:
"Visual inheritance is currently disabled because the base class references
a device-specific component or contains P/Invoke."

Any suggestions?

// The OAC main control
namespace OACFormLibrary
{
   public partial class OAControl : OrientationAwareControl
   {
       public OAControl()
       {
           InitializeComponent();
       }
   }
}

// The form which is fully filled with a OAControl
namespace OACFormLibrary
{
   public partial class OAForm : Form
   {
       public OAForm()
       {
           InitializeComponent();
       }
   }
}

// The testform which inherits from the OAForm
namespace OAFormTest
{
   public partial class MyOAForm : OACFormLibrary.OAForm
   {
       public MyOAForm()
       {
           InitializeComponent();
       }
   }
}

Regards,

Peter