We have seen issues in our implementation with LDAP. Currently squirrelmail searches LDAP with spaces if there are spaces in the person's name. We adapted this by replacing spaces with an asterisk. In our opinion this allows for better searching because you do not have to know the person's name exactly. In the case of someone named "John Smith" who is actually in the ldap database as "Johnathon Smith" the current way would fail but using an asterisk would eliminate this.
ldap space fix