Version Problems (I think)

Hello everyone,

I think I am having a versioning problem that is causing my  
application not to work.  I believe it is this issue that is causing  
the application not to start in JavaMonitor.

The application was compiled written on:

Mac OS X w\ Xcode 2.1, WebObjects 5.3.1 and Java 1.4.2

The application was deployed on:
Solaris 9 w\ WebObjects 5.2.4 and Java 1.4.2

This combination seemed to have worked fine but recently I upgraded  
the software on my Mac OSX to included Java 1.5.0.

The application is now compiled on:

Mac OS X w\ Xcode 2.1, WebObjects 5.3.1 and Java 1.5.0

The application is still deployed on:
Solaris 9 w\ WebObjects 5.2.4 and Java 1.4.2

The only code I changed was a string in the application.  Now for  
some reason the application just dies when I try to run it through  
Java monitor.  Could this be a versioning issue?  Could it be  
something else?  Is there a solution you helpful folks can recommend?

Regards,
Jeff