diff --git a/addressbook/inc/class.addressbook_import_contacts_csv.inc.php b/addressbook/inc/class.addressbook_import_contacts_csv.inc.php
index dbbf75d448..4b54fc000d 100644
--- a/addressbook/inc/class.addressbook_import_contacts_csv.inc.php
+++ b/addressbook/inc/class.addressbook_import_contacts_csv.inc.php
@@ -169,15 +169,20 @@ class addressbook_import_contacts_csv implements importexport_iface_import_plugi
 					switch ( $condition['type'] ) {
 						// exists
 						case 'exists' :
-							$contacts = $this->bocontacts->search(
-								//array( $condition['string'] => $record[$condition['string']],),
-								'', 
-								$_definition->plugin_options['update_cats'] == 'add' ? false : true,
-								'', '', '', false, 'AND', false,
-								array( $condition['string'] => $record[$condition['string']],)
-							);
-
-							if ( is_array( $contacts ) && count( array_keys( $contacts ) >= 1 ) ) {
+							if($record[$condition['string']]) {
+								$searchcondition = array( $condition['string'] => $record[$condition['string']]);
+								// if we use account_id for the condition, we need to set the owner for filtering, as this
+								// enables addressbook_so to decide what backend is to be used
+								if ($condition['string']=='account_id') $searchcondition['owner']=0;
+								$contacts = $this->bocontacts->search(
+									//array( $condition['string'] => $record[$condition['string']],),
+									'', 
+									$_definition->plugin_options['update_cats'] == 'add' ? false : true,
+									'', '', '', false, 'AND', false,
+									$searchcondition
+								);
+							}
+							if ( is_array( $contacts ) && count( array_keys( $contacts ) ) >= 1 ) {
 								// apply action to all contacts matching this exists condition
 								$action = $condition['true'];
 								foreach ( (array)$contacts as $contact ) {
diff --git a/addressbook/inc/class.addressbook_so.inc.php b/addressbook/inc/class.addressbook_so.inc.php
index d6980441a6..4cc650f24c 100755
--- a/addressbook/inc/class.addressbook_so.inc.php
+++ b/addressbook/inc/class.addressbook_so.inc.php
@@ -122,7 +122,7 @@ class addressbook_so
 	var $ldap_search_attributes = array(
 		'n_family','n_middle','n_given','org_name','org_unit',
 		'adr_one_location','adr_two_location','note',
-		'email','mozillasecondemail',
+		'email','mozillasecondemail','uidnumber',
 	);
 	/**
 	 * In SQL we can search all columns, though a view make on real sense