Long time reader first time poster.
I have this program that pulls all Layers, Text, and Blocks (including attribute values) from a set dwgs into Access. I used to use AcadDocument method (keeping the app hidden in the background) and everything worked great. However, out of speed complaints, I switched over to ObjectDBX. Everything, is working great until I try to pull blocks that are embedded in MLeaders. It seems to me that the ContentBlockName property of the MLeader does not work in ObjectDBX. Can anyone else confirm this? If so, does anyone have and clever ideas to get around it?

A short code sample is below. I am using late binding. The code is running in Access 2013 (32-bit) and hitting AutoCAD 2015 (64-bit) on a Win 8.1 machine.
Any help is much appreciated so that I can stop

Dim acadApp As Object 'AcadApplication
Dim acadDBX As Object 'AxDbDocument
Dim acadEnt As Object 'AcadEntity
Dim sBlock As String
Dim O As Object       'AcadEntity

Set acadApp = CreateObject("AutoCAD.Application")

For Each vFile In colFiles
    'This was the old method of opening the document (which worked) Set acadDoc = acadApp.Documents.Open(vFile, False)
    Set acadDBX = acadApp.GetInterfaceObject("ObjectDBX.AxDbDocument." & Left(acadApp.Version, 2))
    acadDBX.Open vFile
    For Each acadEnt In acadDBX.ModelSpace
        Select Case acadEnt.EntityType
            Case 21, 32
                'Do Stuff
            Case 7
                'Do Stuff
            Case 48
                sBlock = acadEnt.ContentBlockName '<<<< This is the line where the error occurs
                For Each O In acadDBX.Blocks(sBlock)
                    If O.ObjectName = "AcDbAttributeDefinition" Then
                        MsgBox acadEnt.GetBlockAttributeValue(O.ObjectID)
                    End If
        End Select
Next vFile