OK, I found this answer in the #zimbra irc room:
1) $vi /opt/zimbra/conf/slapd.conf.in
2) Comment out the "@@ldap_log_level@@" and enter on the next line
3) loglevel 256 (or whatever)
slapindex does not appear to be parsing this variable correctly. Just set it to a static value.
Thanks in advance,
todd_dsm
Don't forget to Vote for this RFE:
RFE: A place To Display the contents of 'My Documents' Reasoning: It's new, bold, and cool.