--- ppa.py.orig	2010-05-14 08:04:25.795738149 +0100
+++ ppa.py	2010-05-14 08:21:02.199879633 +0100
@@ -21,6 +21,7 @@
 
 from threading import Thread
 from urllib2 import urlopen, Request, URLError
+import urllib
 import re
 import subprocess
 import apt_pkg
@@ -43,8 +44,11 @@
     sourceslistd = apt_pkg.Config.FindDir("Dir::Etc::sourceparts")
     line = "deb http://ppa.launchpad.net/%s/%s/ubuntu %s main" % (
         ppa_owner, ppa_name, distro_codename)
+
+    encode = lambda s: urllib.quote(s,'').replace('-','%2D').replace('%','-')
+
     file = "%s/%s-%s-%s.list" % (
-        sourceslistd, ppa_owner, ppa_name, distro_codename)
+        sourceslistd, encode(ppa_owner), encode(ppa_name), encode(distro_codename))
     return (line, file)