Instance Creation

I am unable to create an instance using PDFLibrary in C#.

The dll lives at c:/the project directory/lib/DebenuPDFLibraryDLL1016.dll

I generate the path and also tried hard coding it.

    var dllPath = AppDomain.CurrentDomain.BaseDirectory +     "Lib\\DebenuPDFLibraryDLL1016.dll";

I've included the import file: DebenuPDFLibraryDLL1016.cs

Inside the constructor, dll.dllHandle is always 0. The object is never instantiated.

            dll = new DLL(dllFileName);
            if (dll.dllHandle != IntPtr.Zero)
            {
               instanceID = dll.DebenuPDFLibraryCreateLibrary();
               dll.RegisterForShutdown(instanceID);
            }
            else
            {
               // always gets here
               dll = null;
            }

Does anyone know why this would happen aside from having the wrong location of the dll? I have uninstalled / reinstalled the quick pdf data a few times.