Navigation property "out of memory" exception

We're in the midst of converting our first application using DF2010, so I apologize if it seems as though I'm inundating this forum with posts, but hopefully they'll be of use to future readers, who'll not have to spend the hours upon hours I have debugging...

I'm running into problems with a couple of associations (and their navigation properties).  Almost all of the navigation properties within this application which has about 7 associations work fine, but there seem to be a couple stubborn hold outs.

I'll start by giving you a snippet from the EntityRelations class:

              /// <summary>
        /// Represents the relationship between
        /// <see cref="Holding"/> and <see cref="TaxLot"/>.
        /// </summary>
        /// <remarks>
        /// Relation: FKHoldingTaxLots
        ///        To *: TaxLot (OpenOrdersMaintenance.Data.TaxLot)
        ///        From 0|1: Holding (OpenOrdersMaintenance.Data.Holding)
        /// </remarks>
        public static IbEm.EntityRelation FKHoldingTaxLots = new IbEm.EntityRelation(
              typeof(TaxLot),
              typeof(Holding),            
               new IbEm.DataEntityProperty[] { TaxLot.PropertyMetadata.HoCode },
               new IbEm.DataEntityProperty[] { Holding.PropertyMetadata.HoCode },           
              IbEm.Multiplicity.Many,
              IbEm.Multiplicity.ZeroOrOne,
              IbEm.OnDeleteMode.None,
              IbEm.OnDeleteMode.None,
              "FKHoldingTaxLots");

Given the above relationship, and this snippet (from my test code):

                  // This works
            var holding = Context.EntityManager.Holdings.Where(h => h.HoCode == 807300).FirstOrDefault();
            holding.LoadNavigationProperty("Client");
            holding.LoadNavigationProperty("HoldingTaxLots");

            // This DOES NOT WORK
            //  LoadNavigationProperty does this -> this.EntityAspect.GetRelatedEntity<Holding>(EntityRelations.FKHoldingTaxLots.Role2.Link);
            var taxlot = Context.EntityManager.TaxLots.Where(t=>t.HoCode == 807301).FirstOrDefault();
            taxlot.LoadNavigationProperty("HoldingParent");
            var holdingParent = taxlot.HoldingParent;

The second test (the one that doesn't work) actually DOES work if I run the first test, but if I comment the first test out, the second fails.  When I say "fails", I really mean that this line of code:
  this.EntityAspect.GetRelatedEntity<Holding>(EntityRelations.FKHoldingTaxLots.Role2.Link);
never makes it back and I wind up getting "out of memory" exceptions on subsequent tries to run the app.  DF doesn't throw any exceptions... it just hangs.

I've set up a test project (not the project that contains the code above) that contains both an IdeaBlade model as well as an EF model derived from the same Edmx file, so that I can switch back and forth and what works where.  That project is clean of any developer involvement in terms of extended codegen/business object addons and such.  It's absolutely out of the box so that I can be sure that it's not something that I've screwed up...

The tests above both work fine in EF, but fail in DF.