Comment 2 for bug 622489

I can confirm that. What seems to be happening is that some packages (in my case linux-image-2.6.32-23-virtual) are not in lucid pocket but only in lucid-updates but ubuntu-support-status checks them all against lucid pocket:
(from /usr/bin/ubuntu-support-status)
    # try to figure out the support dates of the release and make
    # sure to look only for stuff in "Ubuntu" and "distro_codename"
    # (to exclude stuff in ubuntu-updates for the support time
    # calculation because the "Release" file time for that gets
    # updated regularly)
    releasef = get_release_filename_for_pkg(cache, pkgname,
                                            "Ubuntu", CODENAME)

in this case get_release_filename_for_pkg returns None and so does the following call to get_release_date_from_release_file. Because of that time_t is unset and exception raised.