[racket] How to get a pict-box into a slideshow?

Robby Findler writes:
 > I am not seeing any hanging, but I did see an error and just pushed a fix for that. How
 > are you getting things to hang?

It's not deterministic, unfortunately. The best recipe I found is this:

   1) Type the following code into DrRacket (or load it from a file):

   #lang slideshow

   (slide
    (t "Hello world")
    )

   2) Put the cursor before the last closing parenthesis.

   3) Insert Pict Box.

   4) Quit DrRacket

This hangs at about every fourth attempt.

I also get the error message "Only pure text files supported", and I
cannot do anything with a pict box other than delete it. I tried
clicking and double-clicking with all three mouse buttons, then I ran
out of ideas. A right-click shows the popup "Cannot show picts: run
program to cache sizes first". But running the program makes no difference.

Konrad.