Index: lib/sqlalchemy/orm/interfaces.py
===================================================================
--- lib/sqlalchemy/orm/interfaces.py    (revision 3507)
+++ lib/sqlalchemy/orm/interfaces.py    (working copy)
@@ -431,7 +431,7 @@
     """
 
     def _get_context_strategy(self, context):
-        return self._get_strategy(context.attributes.get(("loaderstrategy", self), self.strategy.__class__))
+        return self._get_strategy(context.attributes.get(("loaderstrategy", context.path), self.strategy.__class__))
 
     def _get_strategy(self, cls):
         try:
@@ -457,35 +457,6 @@
         if self.is_primary():
             self.strategy.init_class_attribute()
 
-class LoaderStack(object):
-    """a stack object used during load operations to track the 
-    current position among a chain of mappers to eager loaders."""
-    
-    def __init__(self):
-        self.__stack = [       
-    def push_property(self, key):
-        self.__stack.append(key)
-        return tuple(self.__stack)
-        
-    def push_mapper(self, mapper):
-        self.__stack.append(mapper.base_mapper)
-        return tuple(self.__stack)
-        
-    def pop(self):
-        self.__stack.pop()
-        
-    def snapshot(self):
-        """return an 'snapshot' of this stack.
-        
-        this is a tuple form of the stack which can be used as a hash key.
-        """
-        
-        return tuple(self.__stack)
-        
-    def __str__(self):
-        return "->".join([str(s) for s in self.__stack](]
-))
-        
 class OperationContext(object):
     """Serve as a context during a query construction or instance
     loading operation.
@@ -501,9 +472,24 @@
         for opt in util.flatten_iterator(options):
             self.accept_option(opt)
 
+    def push_property(self, key):
+        self.path = self.path + (key)
+        
+    def push_mapper(self, mapper):
+        self.path = self.path + (mapper)
+        
+    def pop(self):
+        self.path = tuple(self.path[-1](-1))
+
     def accept_option(self, opt):
         pass
-
+    
+    def get_path_attribute(self, key):
+        return self.attributes.get((self.path, key))
+    
+    def set_path_attribute(self, key, value):
+        self.attributes[key)]((self.path,) = value
+        
 class MapperOption(object):
     """Describe a modification to an OperationContext or Query."""
 
@@ -580,10 +566,12 @@
         except AttributeError:
             l = [            mapper = context.mapper
+            l.append(mapper)
             for token in self.key.split('.'):
                 prop = mapper.get_property(token, resolve_synonyms=True)
-                l.append(prop)
+                l.append(prop.key)
                 mapper = getattr(prop, 'mapper', None)
+                l.append(mapper)
             self.__prop = l
         return l
 
Index: lib/sqlalchemy/orm/mapper.py
===================================================================
--- lib/sqlalchemy/orm/mapper.py        (revision 3507)
+++ lib/sqlalchemy/orm/mapper.py        (working copy)
@@ -1478,13 +1478,13 @@
     def populate_instance(self, selectcontext, instance, row, ispostselect=None, isnew=False, **flags):
         """populate an instance from a result row."""
 
-        snapshot = selectcontext.stack.push_mapper(self)
+        selectcontext.push_mapper(self)
         # retrieve a set of "row population" functions derived from the MapperProperties attached
         # to this Mapper.  These are keyed in the select context based primarily off the 
         # "snapshot" of the stack, which represents a path from the lead mapper in the query to this one,
         # including relation() names.  the key also includes "self", and allows us to distinguish between
         # other mappers within our inheritance hierarchy
-        populators = selectcontext.attributes.get(((isnew or ispostselect) and 'new_populators' or 'existing_populators', self, snapshot, ispostselect), None)
+        populators = selectcontext.get_path_attribute(((isnew or ispostselect) and 'new_populators' or 'existing_populators', ispostselect), None)
         if populators is None:
             # no populators; therefore this is the first time we are receiving a row for
             # this result set.  issue create_row_processor() on all MapperProperty objects
@@ -1505,8 +1505,8 @@
             if poly_select_loader is not None:
                 post_processors.append(poly_select_loader)
                 
-            selectcontext.attributes[('new_populators', self, snapshot, ispostselect)](]
) = new_populators
-            selectcontext.attributes[self, snapshot, ispostselect)](('existing_populators',) = existing_populators
+            selectcontext.set_path_attribute(('new_populators', ispostselect), new_populators)
+            selectcontext.set_path_attribute(('existing_populators', ispostselect), existing_populators)
             selectcontext.attributes[self, ispostselect)](('post_processors',) = post_processors
             if isnew or ispostselect:
                 populators = new_populators
@@ -1516,7 +1516,7 @@
         for p in populators:
             p(instance, row, ispostselect=ispostselect, isnew=isnew, **flags)
         
-        selectcontext.stack.pop()
+        selectcontext.pop()
             
         if self.non_primary:
             selectcontext.attributes[instance)](('populating_mapper',) = self