I think I've discovered a bug in the new firmware. I'd be grateful if someone else could confirm this.
It relates to third-level submenus. That is, call up a menu in an application. Choose an option that has a second level of options. Choose an option that has a third level. Hit Cancel. The third-level menu refuses to disappear. (It can be made to go away by reselecting the second level.)
There aren't many applications that have such nested menus. It worked fine before the new firmware, though.
R