package in main don't depend on packages from universe, totem Depends on totem-gstreamer | totem-xine, with totem-gstreamer installed by default. You went to that situation because you choiced to activate universe at some stage and install totem-xine from it and then you did activate dapper-updates for universe
-- Latest update of package totem conflicts with totem-xine https://launchpad.net/bugs/55275 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
