IdeaX EAP 102.216 Won't Start on Mac OS X 10.5

I just downloaded the latest EAP build (102.216), but I'm unable to get it to launch.  When I double click the icon, nothing appears to happen.  If I launch the application from the terminal, I get the following error:

$ open /Applications/IdeaX-IU-102.216.app
LSOpenFromURLSpec() failed with error -10810 for the file /Applications/IdeaX-IU-102.216.app.

I've tried setting the IDEA_JDK environment variable (export IDEA_JDK=/System/Library/Frameworks/JavaVM.framework/Versions/1.6/Home), but that seems to have no effect.

Mac OS X 10.5.8

What should I look at next?

Thanks!
David