Comment 11 for bug 446552

Hello Henning, could you please try the following patch:

=== modified file 'UpdateManager/Core/utils.py'
--- UpdateManager/Core/utils.py 2009-01-27 13:48:14 +0000
+++ UpdateManager/Core/utils.py 2009-10-30 11:05:50 +0000
@@ -72,6 +72,10 @@
   (scheme, netloc, path, querry, fragment) = urlparse.urlsplit(uri)
   if scheme == "http":
     import httplib
+ proxy = os.getenv("http_proxy")
+ if (proxy):
+ path = scheme + netloc + path
+ netloc = proxy
     try:
       c = httplib.HTTPConnection(netloc)
       c.request("HEAD", path)
@@ -115,10 +115,10 @@
   * then into gconf (if gconfclient was supplied)
   """
   SYNAPTIC_CONF_FILE = "/root/.synaptic/synaptic.conf"
- proxy = None
+ proxy = os.getenv("http_proxy")
   # generic apt config wins
   apt_pkg.InitConfig()
- if apt_pkg.Config.Find("Acquire::http::Proxy") != '':
+ if not proxy and apt_pkg.Config.Find("Acquire::http::Proxy") != '':
     proxy = apt_pkg.Config.Find("Acquire::http::Proxy")
   # then synaptic
   elif os.path.exists(SYNAPTIC_CONF_FILE):

and see if that helps?