OpenLDAP not listening on port 389

["Ben Stokes" <ben@ukstokes.com>]

I have installed OpenLDAP (openldap-stable-20050429.tgz) and Berkeley DB
(db-4.3.28.NC.tar.gz) on Slackware 10.1. Initially it was working well and I
added a few users, but for some reason now LDAP has stopped responding. Port
389 is closed - "netstat -aplunt | grep 389", shows nothing and I can't
telnet to it. However if I do "ps aux | grep slapd" I can see it running. 

I set "loglevel 4" in my slapd.conf but the only thing that appears in my
log is this: 

"Feb 24 13:39:42 qube slapd[429]: @(#) $OpenLDAP: slapd 2.2.26 (Feb 22 2006
17:07:48) $ ^Iroot@qube:/var/log/ox/openldap-2.2.26/servers/slapd
Feb 24 13:39:45 qube slapd[429]: bdb_db_init: Initializing BDB database"

Which indicates to me that it should be working properly, but I cannot
connect. If I do any kind of search using "ldapsearch" I get:

ldap_bind: Can't contact LDAP server (-1) 

To debug I start LDAP from the command line using "slapd -4 -d 1", it
appears to start OK - but with some references to err2string, I don't know
if this is cause for concern or not.

# slapd -4 -d 1

@(#) $OpenLDAP: slapd 2.2.26 (Feb 22 2006 17:07:48) $
        root@qube:/var/log/ox/openldap-2.2.26/servers/slapd
daemon_init: listen on ldap:///
daemon_init: 1 listeners to open...
ldap_url_parse_ext(ldap:///)
daemon: initialized ldap:///
daemon_init: 1 listeners opened
slapd init: initiated server.
bdb_back_initialize: initialize BDB backend
bdb_back_initialize: Sleepycat Software: Berkeley DB 4.3.28: (April 22,
2005)
>>> dnNormalize: <cn=Subschema>
=> ldap_bv2dn(cn=Subschema,0)
ldap_err2string
<= ldap_bv2dn(cn=Subschema)=0 Success
=> ldap_dn2bv(272)
ldap_err2string
<= ldap_dn2bv(dc=ukstokes,dc=com)=0 Success => ldap_dn2bv(272)

--- etc ---

Is this cause for concern? 

Here is my slapd.conf:

include         /usr/local/openldap/etc/openldap/schema/core.schema
include         /usr/local/openldap/etc/openldap/schema/cosine.schema
include         /usr/local/openldap/etc/openldap/schema/nis.schema
include         /usr/local/openldap/etc/openldap/schema/inetorgperson.schema
include         /usr/local/openxchange/share/openxchange.schema

pidfile         /usr/local/openldap/var/run/slapd.pid
argsfile        /usr/local/openldap/var/run/slapd.args

database        bdb
suffix          "dc=ukstokes,dc=com"
rootdn          "cn=admin,dc=ukstokes,dc=com"
rootpw          secret

directory       /usr/local/openldap/var/openldap-data

index   objectClass     eq
index
uid,mailEnabled,cn,sn,givenname,lnetMailAccess,alias,loginDesti$
index           memberUid eq

access to dn.subtree="ou=Users,ou=OxObjects,dc=ukstokes,dc=com"
           by self write
           by users write
           by anonymous auth

access to dn.subtree="ou=Groups,ou=OxObjects,dc=ukstokes,dc=com"
           by self write
           by users write
           by anonymous auth

#loglevel 4 for high debugging
loglevel 4

I have added "slapd: 127.0.0.1" to my hosts.allow but it has not helped.

Any suggestions at all are welcome, I have posted this on many forums and
had no response, and I've exhausted pretty much everything Google has to
offer. 

Many thanks
Ben