diff --git a/headphones/searcher.py b/headphones/searcher.py
index ec60c3f6..3b53ee47 100644
--- a/headphones/searcher.py
+++ b/headphones/searcher.py
@@ -831,7 +831,7 @@ def searchTorrent(albumid=None, new=False, losslessOnly=False):
                 logger.warn("What.cd credentials incorrect or site is down.")
 
             if whatcd:
-#                whatcd.enableCaching()
+                whatcd.enableCaching()
                 logger.info("Getting artist information for %s..." % artistterm)
                 artist = whatcd.getArtist(artistterm)
                 artist_id = artist.getArtistId()
@@ -855,8 +855,9 @@ def searchTorrent(albumid=None, new=False, losslessOnly=False):
             all_children = []
             for group in release_torrent_groups:
                 logger.info(u"Getting individual torrents for parent ID %s" % group.getTorrentParentId())
-                all_children += group.getTorrentChildren()
-                logger.info(u"Found torrent IDs: %s" % ", ".join(all_children))
+                new_children = group.getTorrentChildren()
+                all_children += new_children
+                logger.info(u"Found torrent IDs: %s" % ", ".join(new_children))
             # cap at 10 matches, 1 per second to reduce hits on API...don't wanna get in trouble.
             # Might want to turn up number of matches later.
 #            max_torrent_info_reads = 10
diff --git a/lib/whatapi.py b/lib/whatapi.py
index 1d612133..ecdcd5cb 100755
--- a/lib/whatapi.py
+++ b/lib/whatapi.py
@@ -36,6 +36,7 @@ import re
 import urllib
 import shelve
 import tempfile
+import threading
 from htmlentitydefs import name2codepoint as n2cp
 
 
@@ -339,17 +340,22 @@ def getWhatcdNetwork(username="", password=""):
 
 class _ShelfCacheBackend(object):
     """Used as a backend for caching cacheable requests."""
+    cache_lock = threading.Lock()
+
     def __init__(self, file_path=None):
         self.shelf = shelve.open(file_path)
 
     def getHTML(self, key):
-        return self.shelf[key]
+        with _ShelfCacheBackend.cache_lock:
+            return self.shelf[key]
 
     def setHTML(self, key, xml_string):
-        self.shelf[key] = xml_string
+        with _ShelfCacheBackend.cache_lock:
+            self.shelf[key] = xml_string
 
     def hasKey(self, key):
-        return key in self.shelf.keys()
+        with _ShelfCacheBackend.cache_lock:
+            return key in self.shelf.keys()
 
 
 class Request(object):