Thanks Aristo.
When I saw your name pop up, was going to scold you for not concentrating on your "homework". (-;
For those interested, forget the thread. Bit of a fiasco. Go directly to Dropbox:
http://db.tt/RhcDaRuD
If that doesn't work I will look for a tall building.
Ixion, next time I'll give this a try. Looks like a great type of puzzle.