If i try the validator http://www.phpbb.com/mods/mpv/ with
http://www.board3.de/temp/board3portal_1_0_0_rc3.zip
i get this error message:

MPV phpBB notice found at functions_compress.php line 334: Unexpected header, ending loop

The same for board3portal_1_0_0_rc2.zip and board3portal_1_0_0_rc1.zip (in the same location).
The archives have been packed with total commander.