NoClassDefFoundError after upgrade to FC3

[Cyrus Adkisson]

Hi everybody. I use jDeveloper from Oracle to program, create GUIs and 
manage my various projects. It's not open-source, but it's a very good 
program. I have been using it without errors for at least a year. Then, 
when I upgraded to Fedora Core 3, it was the only thing on my computer 
that stopped working. When I click on the icon on my desktop, nothing 
pops up, and top shows a massive load on the CPU for "jdev". When I run 
it in a terminal window, I get the following error:

java.lang.NoClassDefFoundError
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:141)
        at oracle.ide.IdeCore.class$(IdeCore.java:89)
        at oracle.ide.IdeCore.startupImpl(IdeCore.java:775)
        at oracle.ide.Ide.startup(Ide.java:539)
        at oracle.jdeveloper.JDeveloper.launch(JDeveloper.java:58)
        at oracle.jdeveloper.JDeveloper.main(JDeveloper.java:37)

I've got the same java SDK I had before, and the configuration files are 
pointing to it. Can anybody think of why an upgrade to Fedora Core 3 
would be causing this error?

Thanks,
Cyrus