[racket] standard-fish mouth-open keyword argument not working

(Oops, repost as I used the wrong email address the first time)

Hello everyone,

Just started to play with Racket and while trying out the slideshow 
library I can't seem to get the standard-fish to open its mouth?

This is what I'm typing in the interactions area:

(standard-fish 80 40 #:direction 'right #:color "red" #:eye-color 
"yellow" #:open-mouth #t)

I get a nice big red fish, but regardless of what the open-mouth keyword 
argument is, the fish's mouth is always closed.  I've tried #t, #f, 0, 
1, 0.5 - none of which seem to have any effect.

Has anyone else experienced this?  I've browsed through pict.rkt but 
can't seem to determine the problem.

Using Racket 5.1.1 on Windows XP.

Regards,
Stephen.