periodically_call_remote renders Page in page

First, I wouldn't use the periodically_call inside the refresh div. I have the feeling that it will vanish at the first call as it will be replaced by the content if the update.
Anyway, if you want to redirect the user to another page, you cannot use redirect because the periodical just replace some portion of the page. So you have to use some JavaScript to tell the browser to change the page location.
Put something like
JavaScript_tag window.location = new/location/whatever.
You may have to check some option to make sure this piece of code will be evaluated.

Pardon my errors or typos, but Im on my mobile without access to reference material.
You should find some info on periodacal on www.prototypejs.org

Good luck
Christophe