diff --git a/CHANGES.txt b/CHANGES.txt
index fb95c50..5b438d0 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,4 +1,6 @@
 v1.40, June 12, 2014 -- Initial public release.
 v1.42, June 19, 2014 -- Removed dependency on simplejson
 v1.43, June 27, 2014 -- Fixed JSON handling issue
+v1.44, July 3, 2014 -- Added show_tracks.py exampole
+v1.45, July 7, 2014 -- Don't used cache auth codes when scope changes
 
diff --git a/examples/util.py b/examples/util.py
index 46e1917..f4726d6 100644
--- a/examples/util.py
+++ b/examples/util.py
@@ -3,6 +3,7 @@
 
 import os
 import subprocess
+import sys
 import spotipy.oauth2 as oauth2
 
 def prompt_for_user_token(username, scope=None):
@@ -15,6 +16,20 @@ def prompt_for_user_token(username, scope=None):
     client_secret = os.getenv('CLIENT_SECRET', 'YOUR_CLIENT_SECRET')
     redirect_uri = os.getenv('REDIRECT_URI', 'YOUR_REDIRECT_URI')
 
+
+    if client_id == 'YOUR_CLIENT_ID':
+        print '''
+            You need to set your Spotify API credentials. You can do this by
+            setting environment variables like so:
+
+            export CLIENT_ID='your-spotify-client-id'
+            export CLIENT_SECRET='your-spotify-client-secret'
+            export REDIRECT_URI='your-app-redirect-url'
+
+            Get your credentials at https://developer.spotify.com/my-applications
+        '''
+        sys.exit(1)
+
     sp_oauth = oauth2.SpotifyOAuth(client_id, client_secret, redirect_uri, 
         scope=scope, cache_path=username)
 
diff --git a/setup.py b/setup.py
index a7f7df3..5beb49b 100644
--- a/setup.py
+++ b/setup.py
@@ -3,7 +3,7 @@ from setuptools import setup
 
 setup(
     name='SpotipyWebApi',
-    version='1.44',
+    version='1.45',
     description='simple client for the Spotify Web API',
     author="@plamere",
     author_email="paul@echonest.com",
diff --git a/spotipy/oauth2.py b/spotipy/oauth2.py
index 09e8f3a..3c01feb 100644
--- a/spotipy/oauth2.py
+++ b/spotipy/oauth2.py
@@ -22,8 +22,8 @@ class SpotifyOAuth(object):
         self.client_secret = client_secret
         self.redirect_uri = redirect_uri
         self.state=state
-        self.scope=scope
         self.cache_path = cache_path
+        self.scope=self.normalize_scope(scope)
    
     def get_cached_token(self):
         token_info = None
@@ -33,8 +33,14 @@ class SpotifyOAuth(object):
                 token_info_string = f.read()
                 f.close()
                 token_info = json.loads(token_info_string)
+
+                # if scopes don't match, then bail
+                if 'scope' not in token_info or self.scope != token_info['scope']:
+                    return None
+
                 if self.is_token_expired(token_info):
                     new_token_info = self.refresh_access_token(token_info['refresh_token'])
+
             except IOError:
                 pass
         return token_info
@@ -86,9 +92,18 @@ class SpotifyOAuth(object):
             raise SpotifyOauthError(response.reason)
         token_info = response.json()
         token_info['expires_at'] = int(time.time()) + token_info['expires_in']
+        token_info['scope'] = self.scope
         self.save_token_info(token_info)
         return token_info
 
+    def normalize_scope(self, scope):
+        if scope:
+            scopes = scope.split()
+            scopes.sort()
+            return ' '.join(scopes)
+        else:
+            return None
+
     def refresh_access_token(self, refresh_token):
         payload = { 'refresh_token': refresh_token,
                    'grant_type': 'refresh_token'}