[Orgmode] org-feed and http_proxy

[zwz]

Now and then I have to set http_proxy for internet access.

I do it in emacs, e.g. by 
(setenv "http_proxy" "http://10.10.10.10:808";)

Ok, now org-feed will use this proxy and works great.

Later, I find the proxy is down, so I switch to another proxy
(setenv "http_proxy" "http://10.10.10.20:808";)

and then M-x org-feed-update-all,
the message shows that org-feed is still using the old proxy
"http://10.10.10.10:808";

I don't know if it is related to org-feed, hope someone has the answer.

By the way, I can not get the feeds from codeproject.
My setting:
("codeproject"
         "http://www.codeproject.com/webservices/articlerss.aspx?cat=2";
         "~/.org/feeds.org" "C++ on CodeProject"
         :parse-feed org-feed-parse-atom-feed :parse-entry 
org-feed-parse-atom-entry)