[ZOPE] External Method process limits?

[Lee Harr]

Hi:

I am trying to learn how to use External Methods by going through
the PIL example from the Zope Book. As a first test, I loaded up
a directory full of photos (jpegs) to make thumbnails of. 
Each image is about 400K.

The makeThumbnail method works fine except when I try it on one
of these images. I am wondering if they are too large...

Here is the error message I get:

Error Type: TypeError
Error Value: expected string, ImplicitAcquirerWrapper found


And the traceback:

Traceback (innermost last):
File /usr/local/www/Zope/lib/python/ZPublisher/Publish.py, line 223, \
in publish_module
File /usr/local/www/Zope/lib/python/ZPublisher/Publish.py, line 187, in publish
File /usr/local/www/Zope/lib/python/Zope/__init__.py, line 221, in \
zpublisher_exception_hook
(Object: Traversable)
File /usr/local/www/Zope/lib/python/ZPublisher/Publish.py, line 171, in publish
File /usr/local/www/Zope/lib/python/ZPublisher/mapply.py, line 160, in mapply
(Object: makeThumbnail)
File /usr/local/www/Zope/lib/python/ZPublisher/Publish.py, line 112, in \
call_object
(Object: makeThumbnail)
File /usr/local/www/Zope/lib/python/Products/ExternalMethod/ExternalMethod.py, \
line 262, in __call__
(Object: makeThumbnail)
(Info: ((<Folder instance at 88ecf80>, 'onea', 128), {}, (128,)))
File /usr/local/www/Zope/Extensions/Thumbnail.py, line 18, in makeThumbnail
(Object: Traversable)
TypeError: (see above)


Any wisdom?