I have a Java class file which imports a class from a third party Jar file...for example:
import org.foo.Person
public class MyPerson {
    public MyPerson() {
        Person p = new Person();
In my Jython code I have...
import MyPerson
class PersonController:
    def __init__(self):
        bob = MyPerson()
Then from interactive Jython I do...
>> import sys
>> sys.path.append("c:\\myProject\\classes")        <--- gives access to MyPerson class file
>> sys.packageManager.addJarDir("c:\\other_stuff\\lib\\", True)    <---- where foo.jar exists
>> from PersonController import *
>> pc = PersonController()

This results in: java.lang.NoClassDefFoundError: java.lang.NoClassDefFoundError: org/foo/Person and it starts from the constructor in my PersonController class where the "MyPerson" is being created. 
I can see that org.foo is imported because in Jython I try:
>> dir(org.foo)

however doing this errors...
>> dir(org.foo.MyPerson)

I know the problem isn't the Java (MyPerson.java) file problem..because i can compile it without error.
Any ideas??