To trzeba było tak od razu.
Dokumentacja:
Cytat
The configuration directives found in a .htaccess file are applied to the directory in which the .htaccess file is found, and to all subdirectories thereof. However, it is important to also remember that there may have been .htaccess files in directories higher up. Directives are applied in the order that they are found. Therefore, a .htaccess file in a particular directory may override directives found in .htaccess files found higher up in the directory tree. And those, in turn, may have overridden directives found yet higher up, or in the main server configuration file itself.
Jedyne wyjście, to utworzenie w podkatalogu pliku
.htaccess, który anuluje ustawienia z katalogu nadrzędnego. Innej możliwości, niestety, nie ma, z tego co wiem i znalazłem.