Comment 1 for bug 479391

This bug is present in Jaunty. I am behind a proxy and use ntlmaps-0.9.9.0.1 to get through our corporate proxy.
Normal updates function correctly thru the proxy.

update-manager version = 1:0.111.10

update-manager does not show an upgrade option 'button'
Software Sources >> Updates >> Release upgrade is selected to "Normal releases"

$ sudo env | grep http_proxy; sudo /usr/bin/do-release-upgrade
http_proxy=http://127.0.0.1:5865/ <== my ntlmaps proxy
Checking for a new ubuntu release
No new release found

Is there a workaround for upgrading from jaunty to karmic?
an apt file to edit? global replace jaunty with karmic ?