Do you mean a value consisting in a single blank? That may cause a lot of errors, and it is practically untestable with OpenLDAP since I believe there are no syntaxes that allow it.
Yes, a value of a single blank.
This backtrace is useless, since it contains no debugging symbols. See http://www.openldap.org/faq/data/cache/56.html for instructions about how to help in tracking issues. Anyway, if my understanding of your issue is correct, now I know what to look for, at least.
Thanks for the link to the gdb instructions.