There are two equal msgid's in apps/l10n and apps/satchmo_store/shop. That raising a conflict - gettext returns wrong translation for the "Subject" in ContactForm from satchmo_store/shop/views/contact.py, that is available at /contact/ url by default.
In l10n app the term "Subject" relates to the structure of a country. Can it be changed there? May be something like "Subject of Federation" (this term used in Russia, "Субъект федерации")?