Passenger/Rails not working. Listing /public directory

Does anyone know if there are some problems with Passenger and/or Ruby on Rails lately. I had a few Rails apps working OK until Monday.

Now, instead of running Passenger, I get a listing of my “/public” files without errors in my logs. It feels like my server doesn’t have Passenger installed. In my own servers I would try to reinstall mod_passenger or a mongrel_cluster, but since this is a shared hosting, I don’t know where to find relevant logs or files that could help me.