PROBLEM: Trouble shooting LDAP connection binding and request resolution
ERROR: "LDAP Bind failure for user . Error -1: Can't contact LDAP server"
SOLVED "Authentication with the LDAP server succeeded."
It means it couldn't connect to the LDAP instance you specified.
If you want a better answer you'll have to provide more details.
I'm not sure if this is the same problem you're having, but you might look at this: http://drupal.org/node/99009