login pre-filter and post data problems

Hello Folks,

I am trying to use a standard sort of login controller, whereby you
put a pre-filter on the pages on which you want the user to have to
login. This is all well an good, except for one thing. Here is some
code to save the original request uri before redirecting to the logon

def authorize
session[:original_uri] = request.request_uri
logger.info("ApplicationController: request_uri

Unfortunatly one of my pages has a form on it with a single "action"
type button. Hence it's a post request, and since it's a post request
it appears that the post data is lost when login redirect happens.
i.e. the line above to save the original_uri isn't sufficient. How
might I remedy this?