Using @request.request_uri

Hey all,
I am facing issues using @request.request_uri. In my before_filter I
get the right value of @request.request_uri, but the value gets
screwed up in after_filter.

if i do session[:return_to]= @request.request_uri

it remains the correct value until before_filter but gets reset to /
in after_filter.

I am struggling with this problem for days and finding solving it

So any help is appreciated