On Fri, 25 Jul 2008, Norman Gaywood wrote:
Jul 25 14:24:54 janus slapd[15043]: conn=19 op=1 RESULT tag=107 err=80 text=DN index delete failed
[...]
http://www.openldap.org/lists/openldap-software/200801/msg00257.html
That all happened around the same time I hit some extremely odd corruption, ITS#5342. The eventual consensus there, as you can read, was chalked up to some previously-standing issue (be them Sleepycat's or OpenLDAP's, or maybe even a lost write on my ATA drive), so there was no real action apart from blowing away the database and slapadd'ing it with the latest version, and no followup necessary in terms of code changes.
If you can figure this out in a reproducible fashion with current releases, that would be interesting. I left off confident that that wouldn't be possible.