Hmm, maybe it's related to this: http://www.openldap.org/its/index.cgi?findid=7495
extra_attrs is a great suggestion. Unfortunately, it doesn't work. If I execute the query and specify an attribute, it returns nothing. If I execute the query and do not specify an attribute, slapd dies, which is what you reported.
-- Russell Mosemann, Ph.D. Professor of Computer Science