Unable to cast object

I got my class working by adding

Implements System.ComponentModel.ISynchronizeInvoke

Do i need to add anything to the following functions?:


   Public Function BeginInvoke(ByVal method As System.Delegate, ByVal args() As Object) As System.IAsyncResult Implements System.ComponentModel.ISynchronizeInvoke.BeginInvoke

    End Function

    Public Function EndInvoke(ByVal result As System.IAsyncResult) As Object Implements System.ComponentModel.ISynchronizeInvoke.EndInvoke

    End Function

    Public Function Invoke(ByVal method As System.Delegate, ByVal args() As Object) As Object Implements System.ComponentModel.ISynchronizeInvoke.Invoke

    End Function

    Public ReadOnly Property InvokeRequired() As Boolean Implements System.ComponentModel.ISynchronizeInvoke.InvokeRequired
        Get

        End Get
    End Property

I'm trying to create a set of generic classes from the SDK .net example. Everything compiles fine but I get the error:

"Unable to cast object of type 'XXX.cls_way2call' to type 'System.ComponentModel.ISynchronizeInvoke'."


It chokes up at:

cls_call.Driver.Device(INT_PROP_DEVICE).Open(0)


I'm not sure exactly what's going on here. Any help would be much appreciated. I've attached a link to the classes below.

http://mattjan.us/cls_call.zip