diff --git a/oml/cache.py b/oml/cache.py
index 88c8443..84e1104 100644
--- a/oml/cache.py
+++ b/oml/cache.py
@@ -18,3 +18,8 @@ class Cache(dict):
         ttl = ttl or self._ttl
         self._added[key] = time.time() + ttl
         dict.__setitem__(self, key, value)
+
+    def delete(self, key):
+        if key in self._addedd:
+            del self._added[key]
+            del self[key]
diff --git a/oml/media/__init__.py b/oml/media/__init__.py
index 5b8fbb1..32e34ba 100644
--- a/oml/media/__init__.py
+++ b/oml/media/__init__.py
@@ -60,7 +60,10 @@ def metadata(f, from_=None):
         data['primaryid'] = ['asin', data['asin'][0]]
     if 'author' in data:
         if isinstance(data['author'], basestring):
-            data['author'] = data['author'].split('; ')
+            if data['author'].strip():
+                data['author'] = data['author'].strip().split('; ')
+            else:
+                del data['author']
         if data['author'] in (['Administrator'], ['Default'], ['user']):
             del data['author']
     if not 'title' in data:
diff --git a/oml/queryparser.py b/oml/queryparser.py
index 05aa828..a7a850c 100644
--- a/oml/queryparser.py
+++ b/oml/queryparser.py
@@ -4,7 +4,6 @@
 from datetime import datetime
 import unicodedata
 from sqlalchemy.sql import operators
-from sqlalchemy.orm import load_only
 
 import utils
 import settings
@@ -41,6 +40,7 @@ class Parser(object):
     def __init__(self, model):
         self._model = model
         self._find = model.find.mapper.class_
+        self._sort = model.sort.mapper.class_
         self._user = model.users.mapper.class_
         self._list = model.lists.mapper.class_
         self.item_keys = model.item_keys
@@ -145,13 +145,15 @@ class Parser(object):
                 return datetime(*[int(i) for i in d])
             #using sort here since find only contains strings
             v = parse_date(v.split('-'))
-            vk = getattr(self._model, 'sort_%s' % k)
+            vk = getattr(self._sort, k)
             q = get_operator(op, 'int')(vk, v)
+            self._joins.append(self._sort)
             if exclude:
                 q = ~q
             return q
         else: #integer, float, time
-            q = get_operator(op, 'int')(getattr(self._model, 'sort_%s'%k), v)
+            q = get_operator(op, 'int')(getattr(self._sort, k), v)
+            self._joins.append(self._sort)
             if exclude:
                 q = ~q
             return q
@@ -232,4 +234,3 @@ class Parser(object):
             qs = qs.filter(c)
         qs = qs.group_by(self._model.id)
         return qs
-