Cache_page throwing "undefined method merge" error

Rails
1

rails (0.14.2), OSX, webrick (right now - lighttpd in production)

I’m trying to cache pages with different file extensions and am having
a heck of a time.

This controller does nothing but display @cache.data (which can be XML
or HTML)

Here’s the controller:

class DisplayController < ApplicationController
caches_page :xml, :html
session :off

def xml
@cache = Cache.find(params[:id])
response.headers[‘content-type’] = @cache.browser_content_type
#cache_page @cache.data, “/display/xml/#{@params[‘id’]}.xml”
end

def html
@cache = Cache.find(params[:id])
response.headers[‘content-type’] = @cache.browser_content_type
#cache_page @cache.data, “/display/html/#{@params[‘id’]}.html”
end

end

If I uncomment the cache_page lines I get these errors:

NoMethodError in
Display#xml
undefined method `merge’ for /display/xml/1.xml

NoMethodError in
Display#html
undefined method `merge’ for /display/html/1.html

I need to set the file extension so that lighttpd sends out the
correct mime type.

Any ideas?