400 Bad Request on new Rails App

I followed the directions on the Dreamhost wiki and used a symlink to point from inside my webspace to a an app in my home directory (‘ln -s …/myapp/public/ myapp’). Does anyone know why I’d get a ‘400 Bad Request’ when going to http://my.domain.com/myapp but everything runs fine when going to http://my.domain.com/myapp/ ?