in the file /var/mailman/Mailman/mm_cfg.py
The entry for
PRIVATE_ARCHIVE_URL = '/mailman/private/'
PRIVATE_ARCHIVE_URL = '/mailman/private'
This is the default in Defaults.py It is overriden in mm_cfg.py
This causes the system to generate broken urls when archives are swtiched
from public to private.
This should be fixed in 2.0.5-1 and later. Thanks!