I can confirm that with the version of apt-cacher in intrepid, 1.6.4ubuntu1, update-manager is prevented from seeing available upgrades when invoked as 'update-manager -d' and have also reproduced the regex warning that occurs. I have also verified that the apt-cacher in intrepid-proposed, 1.6.4ubuntu2, does permit update-manager to see available upgrades. Furthermore, I walked through updating a default intrepid installation with all the outstanding updates and then upgraded the same instance to jaunty (after rebooting) all proxied through the intrepid-proposed apt-cacher, exercising it pretty effectively.
I can confirm that with the version of apt-cacher in intrepid, 1.6.4ubuntu1, update-manager is prevented from seeing available upgrades when invoked as 'update-manager -d' and have also reproduced the regex warning that occurs. I have also verified that the apt-cacher in intrepid-proposed, 1.6.4ubuntu2, does permit update-manager to see available upgrades. Furthermore, I walked through updating a default intrepid installation with all the outstanding updates and then upgraded the same instance to jaunty (after rebooting) all proxied through the intrepid-proposed apt-cacher, exercising it pretty effectively.
Marking verification-done.