since nobody posted it in the request forum...
It would be great to have a config option where the roundcube mail should redirect on logout.
see http://roundcubeforum.net/forum/index.php?topic=388.msg1873#msg1873 (http://roundcubeforum.net/forum/index.php?topic=388.msg1873#msg1873) the described change there works like a charm. but I bet when I will upgrade that I will foget do make the change again.