Jacquie,
It looks like your view can't see the @map instance, any chance you are actually trying to make this call in a partial or that the object wasn't created correctly in the contoller? Can you paste a code snippet for us to look at?
It’s because you are doing a redirect. That is causing to to jump to a new page and start a brand new request, which no longer has all of the code you ran before the redirect in memory. You need to a do a render instead of a redirect.
