Hofmockel.org

Symptom: When you submit a page you receive this error.

user error: Access denied for user 'redpill'@'localhost' to database 'scsf'
query: LOCK TABLES sequences WRITE in /www/html/includes/database.mysql.inc on line 66.

user error: Access denied for user 'redpill'@'localhost' to database 'scsf'
query: LOCK TABLES sequences WRITE in /www/html/includes/database.mysql.inc on line 66.

Symptom: 'Internal Server Error' on new install of Drupal. Removing .htaccess file solves the problem.

The .htaccess file is the only thing in Drupal that can cause an
'Internal Server Error (500)'. This is most likely caused by a
misconfigured or restricted Apache configuration (Some hosts don't
allow PHP directives in .htaccess).

Solution:

Symptom: Event.module has icalendar(webcal) links that are unwanted.
solution: If using PHPtemplate engine - In template.php add
'. l('', $path, array('title' => t('Add this calendar to your iCalendar')), NULL, NULL, TRUE, TRUE) .'';
// return preg_replace("|http://|","webcal://", $ical_link);
}
?>
Change 'mytheme' to the name of your theme.

symptom: User profiles are not visable even when permissions are set properly.

Solution: in user table copy created field to access and login fields where (access or login fields) = 0

ref:  http://drupal.org/node/66653