I think I found a somewhat alarming bug in the Jucer. Be careful when trying this as you may have to power-cycle. Saw it on XP, don’t know about OS X:
Fill in the Member Initialisers field with something having multiple lines – i.e. carriage returns
Save the file
Quickly do a force-quit (if you can) before the Jucer completely freezes your machine
The second time this happened, I had to forcibly power-cycle my computer. But that’s XP’s fault for allowing a runaway user process to hijack the system. Amateurs.