Ubuntu 12.04 LTS "Precise Pangolin" released

Even so, the lp bug shouldn't be marked as closed (and certainly not Invalid!). At least on BZ, CLOSED bugs need an extra step to search for, so keeping it open with a reference to the upstream bug is always better than closing the bug if it isn't actually fixed in Ubuntu. The reporter can come back to lp (though I would say that the maintainer should probably at least go CC'd on the upstream bug) and notify the maintainer that a fix is available. At that point the maintainer can decide whether it's important enough to backport or just wait for the next version.