diff --git a/presentation/lookAndFeel/knowledgeTree/administration/usermanagement/listUsersUI.inc b/presentation/lookAndFeel/knowledgeTree/administration/usermanagement/listUsersUI.inc
index e3580ad..ca49217 100644
--- a/presentation/lookAndFeel/knowledgeTree/administration/usermanagement/listUsersUI.inc
+++ b/presentation/lookAndFeel/knowledgeTree/administration/usermanagement/listUsersUI.inc
@@ -49,11 +49,12 @@ function getGroupDisplay($iGroupID) {
 
 function getUsers($fGroupID) {
 	global $default;
+	// changed from inner to outer joins to include users that aren't in any groups (Stefano Ciancio [s.ciancio@pisa.iol.it]) 
 	$sQuery = 	"SELECT DISTINCT U.id as userID, U.name as name, U.username, " . 
 				"'Edit', 'Delete', 'Edit Groups' " .
 				"FROM $default->users_table U " . 
-				"INNER JOIN $default->users_groups_table UGL ON U.id = UGL.user_id " .
-				"INNER JOIN $default->groups_table GL ON UGL.group_id = GL.id ";
+				"LEFT OUTER JOIN $default->users_groups_table UGL ON U.id = UGL.user_id " .
+				"LEFT OUTER JOIN $default->groups_table GL ON UGL.group_id = GL.id ";
 	// filter by group				
 	if ($fGroupID) {
 		$sWhereClause = "WHERE UGL.group_id = $fGroupID ";