[Zope] External Methods triggers Zope restart

[myers@crd.ge.com]

I am having a frustrating problem with External Methods.
I have regressed to Zope 2.4.0 to try to resolve this.

Basically, the following external method works:

def helloWorld():
    """A simple external method."""
    return 'Hello World!'

But the following method causes Zope to restart with no traceback:
def helloWorld():
    """A simple external method."""
    a = 'Hello World!'
    return a

If I use self.a instead of just a, the method works.  
I used th epython debugger, and the correct HTML is displayed in both 
cases.  I don't find anything usefull in the -M log either.

Has anyone seen anything like this, or have any ideas where I should 
look next.

Thanks, 

Paul


OS:  HP-UX 10.20
Python 2.1.1
Zope 2.4.0