AutoMapper 2.1.267.0 does not map simple int? property

Question

I have the following classes

Source:

public class NewBusinessSubmission
{
    //other properties      
    public int? TermTypeId { get; set; }

}

Destination:

NewBusinessSubmission class inherits from the PolicyTransaction class shown below (yes it is VB.NET):

<System.Serializable()> Public MustInherit Class PolicyTransaction
    Inherits Framework2.BusinessBase(Of PolicyTransaction)
    Implements IDisposable

  ...........

Public Property TermTypeId() As Nullable(Of Integer)
    Get
        CanReadProperty(True)
        If Not _PolicyTermsDataRow.IsTermTypeIdNull Then
            Return Me._PolicyTermsDataRow.TermTypeId
        End If
    End Get
    Set(ByVal value As Nullable(Of Integer))
        If Nullable(Of Integer).Equals(value, Me.TermTypeId) Then Exit Property
        CanWriteProperty(True)
        If value.HasValue Then
            Me._PolicyTermsDataRow.TermTypeId = value.Value
        Else
            Me._PolicyTermsDataRow.SetTermTypeIdNull()
        End If
        AfterTermTypeIdChanged()
        Me.PropertyHasChanged()
    End Set
End Property
  ...........


End Class

Mapping Configuration below does not set the TermTypeId:

    Mapper.CreateMap<NewBusinessSubmission, NewBusiness>()
        .ForMember(x => x.PolicyTxnNum, opt => opt.Ignore())
        .ForMember(x => x.ContactProducerLicId, opt => opt.Ignore())
        .ForMember(x => x.PolicyNames, opt => opt.Ignore())
        .ForMember(x => x.PolicyExp, opt => opt.Ignore());

This one does not work either:

    Mapper.CreateMap<NewBusinessSubmission, NewBusiness>()
        .ForMember(x => x.PolicyTxnNum, opt => opt.Ignore())
        .ForMember(x => x.ContactProducerLicId, opt => opt.Ignore())
        .ForMember(x => x.PolicyNames, opt => opt.Ignore())
        .ForMember(x => x.PolicyExp, opt => opt.Ignore())
        .ForMember(x => x.TermTypeId, opt => opt.MapFrom(x => x.TermTypeId));

I call Map like this:

        var newBusiness = Mapper.Map<NewBusinessSubmission, NewBusiness>(newBusinessSubmission);

All the other properties that have similar code in the Set() method map correctly and I can also manually map TermTypeId like this:

        newBusinessInstance.TermTypeId = newBusinessSubmissionInstance.TermTypeId;

Any ideas as to why this property is not mapped correctly?

Thanks.