"The point of my question was if I needed to do something to keep up with the changes made in Arc."
Then making sure Racket is up-to-date is the answer you're looking for, as you already know. :-p Have you been successful running the latest Anarki on your Racket install yet? What do "racket --version" and "mzscheme --version" say now?
Hi,
Thanks a lot to your earlier comment, about running "racket -f as.scm"- I found out that racket couldnt be located by the system. Something must be unclear with the description of Ubuntu/Debian packages- I got an impression that "plt-scheme" contained racket. I manually installed racket by downloading from here: http://racket-lang.org/download/ .