Index: modules/comment/comment.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/comment/comment.module,v
retrieving revision 1.810
diff -u -p -r1.810 comment.module
--- modules/comment/comment.module	28 Nov 2009 16:41:19 -0000	1.810
+++ modules/comment/comment.module	1 Dec 2009 11:13:45 -0000
@@ -1944,7 +1944,7 @@ function comment_form_validate($form, &$
         $query = db_select('users', 'u');
         $query->addField('u', 'uid', 'uid');
         $taken = $query
-          ->where('LOWER(name) = :name', array(':name' => $form_state['values']['name']))
+          ->condition('name', $form_state['values']['name'], 'LIKE')
           ->countQuery()
           ->execute()
           ->fetchField();
Index: modules/profile/profile.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/profile/profile.module,v
retrieving revision 1.281
diff -u -p -r1.281 profile.module
--- modules/profile/profile.module	1 Nov 2009 21:26:44 -0000	1.281
+++ modules/profile/profile.module	1 Dec 2009 11:14:05 -0000
@@ -609,8 +609,7 @@ function _profile_get_fields($category, 
     $query->condition('register', 1);
   }
   else {
-    // Use LOWER(:category) instead of PHP's strtolower() to avoid UTF-8 conversion issues.
-    $query->where('LOWER(category) = LOWER(:category)', array(':category' => $category));
+    $query->condition('category', $category, 'LIKE');
   }
   if (!user_access('administer users')) {
     $query->condition('visibility', PROFILE_HIDDEN, '<>');
Index: modules/user/user.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/user/user.module,v
retrieving revision 1.1084
diff -u -p -r1.1084 user.module
--- modules/user/user.module	22 Nov 2009 04:22:54 -0000	1.1084
+++ modules/user/user.module	1 Dec 2009 11:14:24 -0000
@@ -714,9 +714,12 @@ function user_access($string, $account =
  * @return boolean TRUE for blocked users, FALSE for active.
  */
 function user_is_blocked($name) {
-  $deny = db_query("SELECT name FROM {users} WHERE status = 0 AND name = LOWER(:name)", array(':name' => $name))->fetchObject();
-
-  return $deny;
+  return db_select('users')
+    ->fields('users', array('name'))
+    ->condition('name', $name, 'LIKE')
+    ->condition('status', 0)
+    ->execute()
+    ->fetchObject();
 }
 
 /**