Error when trying to Start VM

I'm trying to debug a swing app which is essentially a JAR file...

ERROR: Cause of death:
Error[22] in gethostbyname() call!
err:: Invalid argument
Socket Transport failed to init
Transport dt_socket failed to initialize, rc =-1.
FATAL ERROR in native method: No transports initialized

In the Start VM dialog box I have my Java Home set, the JVM executable is
java and for the class name I give the pacakage name and class which
launches the application.

I'm having this issue on my Mac OS X powerbook (not that it should
matter). I mention this only b/c I have jSwat set up on my Windows box as
well and with the exact same settings (AFAIK) (sourcepath, classpath) and
it runs fine on the Windows machine and loads/starts up the app just
great. But running it on my Mac fails with the above error.

Any ideas as to what I have wrong?

Thanks for any help!

- Billy -