Java Web Start - NoClassDefFoundError - strange path

[JW]

Hi,

I used JBuilder to create a Web Start launchable Java Application. My
application .jar file contains classes from 2 packages, one of which
is call "data".

I start the Tomcat server from JBuilder and try launching my
application from a web browser on the same machine. However, Web Start
shows me the following error:

java.lang.NoClassDefFoundError: data/generated/DataUnitCollection

Here's my confusion. "DataUnitCollection" is a class within the
package (or directory) "data", and that class is in the .jar file. I
was hoping someone can explain to me where the "/generated/" part of
the path in the error comes from?

The machine I tried this on is running Windows XP

Thanks