find(:all) problem when using rss builder

I have an index page that displays the newest contents of a table called ratings. The controller code looks like this:


    def index       @newratings = Rating.find(:all, :order => "twitter_num DESC", :limit => 20)

     # . . . some other code . . .

     respond_to do |format|        format.html        format.rss {render :layout => false}     end   end [/code]

This works when I load index.html.erb, but when I try to load index.rss.builder, it just downloads an error page instead of an rss feed. When I check the log, this is the error:

    [quote] ActiveRecord::StatementInvalid (Mysql::Error: Table     'twitterate.ratings' doesn't exist: SELECT * FROM `ratings` ORDER     BY twitter_num DESC LIMIT 20): [/quote]

This doesn't make sense to me; how can it not realize that the table exists when it queries from it just fine when the same controller code is called from the other view template? To make it even weirder, I have a nearly identical setup with the 'show' method (does the same thing but for a single user) and it works fine when generating the rss.