This thread led me to believe that subsonic 4.1 would not run on my Mac server running OS X 10.4.11 and Java 1.5.0.
However, I just gave it a go to see what would happen and everything seemed to work just fine! here's a screen capture of the info page showing subsonic 4.1 running on a machine with java 1.5.0_19...

I'm certainly not complaining that it works!
