Filter does not get sent

[kinghrothgar]

I'm trying to use the :filter option to limit access to uniqueMember of a group. Here is my config:

  :host => 'escapemg.com',
  :port => 389,
  :method => :plain,
  :base => 'dc=escapemg,dc=com',
  :filter => '(&(cn=techdocs)(uniqueMember=uid=%{username},ou=ZimbraUsers,dc=escapemg,dc=com))',
  :name_proc => Proc.new {|name| name.gsub(/@.*$/,'')},
  :bind_dn => 'cn=Directory Manager',
  :password => 'blahblahblah'

I tcpdumped what it was sending to the ldap server and it never sends the filter. It sends (objectclass=*) and then authentication fails. Am I doing something wrong or is this a bug?