In case anyone else comes along, I had the same problem using Apache 2.4.6 (Ubuntu). It had to do with apache not having permission to /usr/lib/iipimage-server. I simply copied that to /usr/share/iipimage-server and adjusted the path in iipsrv.conf and the url worked.
I've been thinking about the best approach to implement pure function verification in the Scala compiler. An approach similar to the one in D would fit a lot better than the one used in Haskell (which would break all existing code and cause some problems due to strict evaluation). A solution using annotations would be quite simple to implement: