Index: auto_username.module
===================================================================
--- auto_username.module	(revision 1994)
+++ auto_username.module	(working copy)
@@ -49,7 +49,14 @@
     '#title' => t('Other options'),
     '#collapsible' => TRUE,
     '#collapsed' => FALSE,
-  );
+  );     
+  $form['aun_settings']['aun_exclude_roles'] = array(
+    '#type' => 'checkboxes',
+    '#options' => user_roles(true),
+    '#title' => t('Exclusion Roles'),
+    '#default_value' => variable_get('aun_exclude_roles', ''),
+    '#description' => t("Defines roles which will NOT be affected by auto_username."),
+  ); 
   $form['aun_settings']['aun_php'] = array(
     '#type' => 'checkbox',
     '#title' => t('Evaluate PHP in pattern.'),
@@ -121,7 +128,7 @@
  */
 function auto_username_user($op, &$edit, &$account, $category = NULL) {
   static $new_name;
-
+  
   switch ($op) {
     case 'validate':
       $new_name = _auto_username_patternprocessor($account);
@@ -144,10 +151,16 @@
       break;
 
     case 'insert':
+      // if in one of our Exclusionary roles - do nothing
+      if (_aun_check_role($account)) break;
+      
       db_query("UPDATE {users} SET name='%s' WHERE uid=%d", array($new_name, $account->uid));
       break;
 
     case 'after_update':
+      // if in one of our Exclusionary roles - do nothing
+      if (_aun_check_role($account)) break;
+    
       // Only process on update if we're configured to do so.
       // We have to use after_update here instead of the 'update' op because
       // update happens before user module does its own saving.  Anything we do
@@ -306,7 +319,7 @@
  * Implementation of hook_form_alter().
  */
 function auto_username_form_alter($form_id, &$form) {
-  if ('user_register' == $form_id) {
+  if ($form_id == 'user_register') {
     // Fake a real user name submission, because we have to validate against
     // the bulit-in username validation even though we're going to change the
     // name anyway.
@@ -320,7 +333,11 @@
     $form['#submit']['auto_username_user_register_submit'] = array();
   }
 
-  if ('user_edit' == $form_id && variable_get('aun_update_on_edit', 1)) {
+  if ($form_id == 'user_edit' && variable_get('aun_update_on_edit', 1)) {
+    // if in one of our Exclusionary roles - do nothing
+    $account = user_load(array('uid'=>arg(1)));
+    if (_aun_check_role($account)) return;
+    
     // The username may not be editable.
     if (isset($form['account']['name'])) {
       $form['account']['name'] = array(
@@ -453,3 +470,15 @@
   }
 }
 
+// helper function to check if user belongs to exclusionary role
+function _aun_check_role(&$account) {
+  // if in one of our Exclusionary roles - return now
+  $roles = variable_get('aun_exclude_roles', 0);
+  foreach ($roles as $key => $role) if (!$role) unset($roles[$key]);
+  
+  foreach ($account->roles as $roleid => $name) {
+    if (in_array($roleid, $roles)) return true;
+  }
+  
+  return false;
+}
\ No newline at end of file