I'm not completly sure, but... There are some timezones in the Anaconda's POT file which should be translated (generated from zone.tab). But timezones are taken from system-config-date/timezones POT file (like the screen for timezone config where Anaconda is taking translations from system-config-date and timezone list from system-config-date/timezones). This seems to me like Anaconda's POT file contain old timezone list (in zone.tab). Please check it out and remove unneded strings for translation if the complete timezone selection is now from system-config-date package. Also consider to commit translations and rebuild system-config-date by daily/weekly basis to allow translations to appear in the devel tree (to allow to test them by Fedora translators in the test cycle for FC7).
The strings were being included from /usr/share/zoneinfo/zone.tab for text mode installs but we can easily get around having that by just including the system-config-date .mo files in the text environment. This will be fixed in the next build of anaconda.