Then check the output for "these packages have been held back:", and either "apt-get --purge remove" each of them (if you don't want them), or "apt-get install" them (if you do want them).
You can also "apt-get dist-upgrade" (which will autoinstall new dependencies and autoremove conflicting packages), but that has been known to go wild removing tons of packages just because of a simple KDE or gcc upgrade. Or at least, it's done it to me (though maybe that's because the machine started off as a Knoppix hdinstall, not a Debian system -- Knoppix was faster to get up and running).
I have a script in cron.daily that does an "apt-get update && apt-get upgrade" (actually, with a few other options to make it work well in the script); cron mails me the output when it runs each day. |