caches_action not generating full parameter route

Hi there, I have a URL like this: /artworks/show/4 I've turned on caching in development mode, and my controller says:

  caches_action :index, :list, :show

as well as

  def show     @artwork = @artist.artworks.find(params[:id], :include => :tags)     @tags = @artwork.tags   end

but for some reason i only ever get the cache file: /artworks/show.cache with no id parameter

I'm running 1.2.3 anyone have any ideas?

thanks dorian

ok, I answered that myself. I had a route that was biting before the one I was expecting. note to self - check routes, regularly.