If you find bug, please report to Forums or Ticket system.
You can check integrity of files by SHA1 hashes. It signed by OpenPGP key of t_mrc-ct[at]users.sourceforge.jp. The public key could get from here or OpenPGP Keysever.
All Langpacks have not been updated since v31.0. You can use these on Tenfourbird 31.1.0.