Seeing as how I have yet to be able to get the new LDAP package working that is available in the vtiger forums I went ahead and modified the original 5.1 LDAP auth to get it working with 5.2. So if you are in the same situation as I was here is my fix for LDAP auth in 5.2.

• Install PHP LDAP support:

  apt-get install php5-ldap

• Download VTiger 5.2.0 LDAP support files and extract:

  cd /var/www
  wget http://wiki.itadmins.net/lib/exe/fetch.php?media=vtigercrm:vtiger-ldap-integration-v1.1.zip
  unzip vtiger-ldap-integration-v1.1.zip

vtiger-ldap-integration-v1.1.zip - This LDAP package is a slightly modified version of the v1.0 LDAP files from vtiger. 5.2.0 has a few new variables that need passing when creating a user and I have modified these to reflect that.

• Change LDAP config settings in /var/www/include/ldap/config.ldap.php

• Enjoy! ;)