I think the best way to approach the issue will be, to test supported locales/languages at start, and only list the available ones in the language selection. Current code just scans for po files, which is wrong anyway.
We could also drop the selection altogether, and go for system default maybe. It would make testing translations less convenient though (need to change current system locale).
Looking at gettext docs it seems that locale selection is not trivial:
http://www.gnu.org/software/libc/manual/...tware.html
Also:
http://www.heiner-eichmann.de/autotools/...ttext.html