[plt-scheme] release-snip doesn't trigger resized

This is another oddity that I don't know whether or not it's a bug or just 
my miss understanding. This program inserts a snip, s5, and then releases it 
which leaves the pasteboard, ap, the same size as it was. If I move s5 
instead of releasing it, ap and its containing snip get smaller. If this is 
not a bug which I'll wager it's not, does anyone know how I can poke ap to 
get smaller in the case where I'm releasing s5? I would like for ap to get 
this update and shrink the way it does when I move s5.

(require
 (lib "class.ss")
 (lib "mred.ss" "mred"))

(define f (new frame% (label "f") (width 400) (height 400)))
(define e (new text%))
(define c (new editor-canvas% (parent f) (editor e)))
(define ap (new pasteboard%))
(define es (new editor-snip% (editor ap)))
(define s5 (make-object string-snip% "s5"))
(define switch-me? #f)

(send f show #t)
(send e insert es)

(send* ap
  (insert s5)
  (move-to s5 15.0 13.0))

(if switch-me?
    (send ap release-snip s5)
    (send ap move-to s5 0 0))