I installed the OpenSearch plugin, and it works, but it doesn't search multiple words. For example, if I search "music", it works fine and displays the results in my Drupal site, but if I were to search "music library", it returns the 404 error page.

I figured out the reason it does this is because once the search is performed using the plugin, it does, for example: "http://mysite/search/node/music+library", and I guess the plus sign is what makes it return the error page. But if somehow the search were to be performed like this: "http://mysite/search/node/music library", it would work.

Does anyone know a way to fix this?