The Slovene translation has an incorrect string in its crashreporter.ini which cause the strings to be displayed as "?" when the crash reporter is shown. The solution is to replace '%S' with '%s' (i.e. lower-case the letter s). The affected string are: Restart l10-mozilla-1.9.1, l10n-mozilla-1.9.2 and l10n-mozilla-central are affected. If you wish to test your translation once completed, you can use the "crash me" extension available from here: http://code.google.com/p/crashme/ (this will install a menu option from which you can force Firefox or Thunderbird to crash).
We don't work with mozilla-central, all releases are copied initially from working branches. So closing this off.