Very very useful plugin!
1) Works great... but only under PHP5. For PHP4 users you must modify file mospasswort.php located in "plugins/content" directory: change line #37:

$mosConfig_lang = &JFactory::getLanguage()->getBackwardLang();

to

$mosTemp=&JFactory::getLanguage();
$mosConfig_lang = $mosTemp->getBackwardLang();

After that code works fine in both PHP4 and PHP5, so it's advisable for the author to implement this changes in the original package.

2) multilingual approach is hard-coded in the source file mospasswort.php. Instead of that, it's better to allow the user enter desired language-specific words in properties of the plugin at Joomla administrator panel. By doing this, it's possible to use JoomFish! or other extensions to display multilingual web-sites.

Once again, it's a great plugin!