Error signing up to a list

Hi OGN people,

I've just had a report of someone failing to sign up to pa-dev on
lists.peopleaggregator.org, receiving an AssertionError from Zope (full
traceback pasted below) on the following URL:


http://lists.peopleaggregator.org/Scripts/set/subscribe_group?division_id=peopleaggregator&group_id=pa-dev

Cheers,
Phil


    Site Error

An error was encountered while publishing this resource.

*AssertionError*

Sorry, a site error occurred.

Traceback (innermost last):

    * Module ZPublisher.Publish, line 194, in publish_module_standard
    * Module ZPublisher.Publish, line 146, in publish
    * Module Zope2.App.startup, line 222, in zpublisher_exception_hook
    * Module ZPublisher.Publish, line 115, in publish
    * Module ZPublisher.mapply, line 88, in mapply
    * Module ZPublisher.Publish, line 41, in call_object
    * Module Products.FileSystemSite.FSPythonScript, line 104, in __call__
    * Module Shared.DC.Scripts.Bindings, line 311, in __call__
    * Module Shared.DC.Scripts.Bindings, line 348, in _bindAndExec
    * Module Products.FileSystemSite.FSPythonScript, line 160, in _exec
    * Module None, line 22, in subscribe_group
      *<FSPythonScript at /sites/onlinegroups/Scripts/set/subscribe_group>*
      *Line 22*
    * Module Products.CustomUserFolder.CustomUserFolder, line 210, in
      getUser

AssertionError: User ID not set

------------------------------------------------------------------------

Troubleshooting Suggestions

    * The URL may be incorrect.
    * The parameters passed to this resource may be incorrect.
    * A resource that this resource relies on may be encountering an error.

For more detailed information about the error, please refer to the error
log.

If the error persists please contact the site maintainer. Thank you for
your patience.