I am also a late upgrader from Lenny to Squeeze I have the same problem here Is there a way to get the upgrade done?
Upgrading the package slapd from Lenny 2.4.11-1+lenny2.1 to 2.4.23-7.3 fails: Setting up slapd (2.4.23-7.3) ... Backing up /etc/ldap/slapd.conf in /var/backups/slapd-2.4.11-1+lenny2.1... done. Moving old database directories to /var/backups: Loading from /var/backups/slapd-2.4.11-1+lenny2.1: - directory dc=ccc,dc=com... failed. Loading the database from the LDIF dump failed with the following error while running slapadd: /var/backups/slapd-2.4.11-1+lenny2.1/dc=uni-graz,dc=at.ldif: No such file or directory dpkg: error processing slapd (--configure): subprocess installed post-installation script returned error exit status 1 configured to not write apport reports Errors were encountered while processing: slapd E: Sub-process /usr/bin/dpkg returned an error code (1) A package failed to install. Trying to recover: Setting up slapd (2.4.23-7.3) ... Backing up /etc/ldap/slapd.conf in /var/backups/slapd-2.4.11-1+lenny2.1... done. Moving old database directories to /var/backups: Loading from /var/backups/slapd-2.4.11-1+lenny2.1: - directory dc=ccc,dc=com... failed. Loading the database from the LDIF dump failed with the following error while running slapadd: /var/backups/slapd-2.4.11-1+lenny2.1/dc=uni-graz,dc=at.ldif: No such file or directory dpkg: error processing slapd (--configure): subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing: slapd