`'root` menu bar has some problems

[rfindler]

There seem to be two problems (or two symptoms of the same problem).

1. run this first program and then close the window. The type cmd-o. This should produce the printout "open", but it beeps instead.

#lang racket/gui
(define mb (new menu-bar% [parent 'root]))
(define m (new menu% [label "File"] [parent mb]))
(define mi (new menu-item% [parent m] [label "Open"] [shortcut #\o] [callback (λ x (printf "open\n"))]))
(define f (new frame% [label "frame"] [width 100] [height 100]))
(send f show #t)
(yield (make-semaphore 0))

2. this second program should show the root menu bar, but when running racket f.rkt (where f.rkt contains this program) from the command line doesn't do that. It just seems to keep the previous menu bar from whatever app you used to run racket.

#lang racket/gui
(define mb (new menu-bar% [parent 'root]))
(define m (new menu% [label "File"] [parent mb]))
(define mi (new menu-item% [parent m] [label "Open"] [shortcut #\o] [callback (λ x (printf "open\n"))]))
(yield (make-semaphore 0))