If a url query has a field names that contain a dot (e.g. openid.assoc_handle), bad stuff happens.
For example: try http://www.object-craft.com.au/cgi-bin/alsamp/form4/form.py?funny.field=told+you+so
Update
andrewm gave me advice how to solve the openid problem by doing self.locals.openid=albatross.context.Vars() during context class constructor:
http://www.object-craft.com.au/pipermail/albatross-users/2007-March/001294.html
It worked, but it still feels like a patch to me. Maybe it's an acquired taste 