diff --git a/mongoengine/connection.py b/mongoengine/connection.py
index ee8d735b..da8f2baf 100644
--- a/mongoengine/connection.py
+++ b/mongoengine/connection.py
@@ -7,7 +7,6 @@ __all__ = ['ConnectionError', 'connect']
 _connection_settings = {
     'host': 'localhost',
     'port': 27017,
-    'pool_size': 1,
 }
 _connection = None
 
diff --git a/mongoengine/document.py b/mongoengine/document.py
index 357c8bc7..8fdb88db 100644
--- a/mongoengine/document.py
+++ b/mongoengine/document.py
@@ -78,9 +78,9 @@ class Document(BaseDocument):
                 object_id = collection.save(doc, safe=safe)
         except pymongo.errors.OperationFailure, err:
             message = 'Could not save document (%s)'
-            if u'duplicate key' in err.message:
+            if u'duplicate key' in unicode(err):
                 message = u'Tried to save duplicate unique keys (%s)'
-            raise OperationError(message % err.message)
+            raise OperationError(message % unicode(err))
         id_field = self._meta['id_field']
         self[id_field] = self._fields[id_field].to_python(object_id)
 
@@ -95,7 +95,8 @@ class Document(BaseDocument):
         try:
             self.__class__.objects(**{id_field: object_id}).delete(safe=safe)
         except pymongo.errors.OperationFailure, err:
-            raise OperationError(u'Could not delete document (%s)' % err.message)
+            message = u'Could not delete document (%s)' % err.message
+            raise OperationError(message)
 
     def reload(self):
         """Reloads all attributes from the database.
diff --git a/mongoengine/fields.py b/mongoengine/fields.py
index a0374c4e..4695bf81 100644
--- a/mongoengine/fields.py
+++ b/mongoengine/fields.py
@@ -71,7 +71,8 @@ class FloatField(BaseField):
         return float(value)
 
     def validate(self, value):
-        if isinstance(value, int): value = float(value)
+        if isinstance(value, int):
+            value = float(value)
         assert isinstance(value, float)
 
         if self.min_value is not None and value < self.min_value:
diff --git a/mongoengine/queryset.py b/mongoengine/queryset.py
index a42690a5..e88804f9 100644
--- a/mongoengine/queryset.py
+++ b/mongoengine/queryset.py
@@ -520,9 +520,10 @@ class QuerySet(object):
             self._collection.update(self._query, update, safe=safe_update, 
                                     multi=True)
         except pymongo.errors.OperationFailure, err:
-            if err.message == u'multi not coded yet':
-                raise OperationError(u'update() method requires MongoDB 1.1.3+')
-            raise OperationError(u'Update failed (%s)' % err.message)
+            if unicode(err) == u'multi not coded yet':
+                message = u'update() method requires MongoDB 1.1.3+'
+                raise OperationError(message)
+            raise OperationError(u'Update failed (%s)' % unicode(err))
 
     def update_one(self, safe_update=True, **update):
         """Perform an atomic update on first field matched by the query.
diff --git a/tests/fields.py b/tests/fields.py
index 7949cc36..b35a9142 100644
--- a/tests/fields.py
+++ b/tests/fields.py
@@ -106,7 +106,7 @@ class FieldTest(unittest.TestCase):
         person.height = 1.89
         person.validate()
 
-        person.height = 2
+        person.height = '2.0'
         self.assertRaises(ValidationError, person.validate)
         person.height = 0.01
         self.assertRaises(ValidationError, person.validate)
diff --git a/tests/queryset.py b/tests/queryset.py
index 6d45bdae..b6e958a2 100644
--- a/tests/queryset.py
+++ b/tests/queryset.py
@@ -21,7 +21,7 @@ class QuerySetTest(unittest.TestCase):
         """Ensure that a QuerySet is correctly initialised by QuerySetManager.
         """
         self.assertTrue(isinstance(self.Person.objects, QuerySet))
-        self.assertEqual(self.Person.objects._collection.name(), 
+        self.assertEqual(self.Person.objects._collection.name, 
                          self.Person._meta['collection'])
         self.assertTrue(isinstance(self.Person.objects._collection,
                                    pymongo.collection.Collection))
@@ -294,6 +294,8 @@ class QuerySetTest(unittest.TestCase):
         BlogPost.drop_collection()
 
     def test_q(self):
+        """Ensure that Q objects may be used to query for documents.
+        """
         class BlogPost(Document):
             publish_date = DateTimeField()
             published = BooleanField()
@@ -618,6 +620,8 @@ class QuerySetTest(unittest.TestCase):
 class QTest(unittest.TestCase):
     
     def test_or_and(self):
+        """Ensure that Q objects may be combined correctly.
+        """
         q1 = Q(name='test')
         q2 = Q(age__gte=18)