this configuration works for me:

Settings->Additional settings->(Authentification settings list) View List:
Domain: Username Password
http://*rapidshare.com <rapidshare account> shared
http://*.rapidshare.com <rapidshare account> shared

(2 domains definitions needed - "redirecton on rapidshare to mirror? - finaly file dowloaded from something like http://w23kkke.rapidshare.com/...."). I don't know why (probably bug) 1st definition (http://*rapidshare.com) dosn't cover also the redirected URL (http://w23kkke.rapidshare.com).