diff -u includes/install.core.inc includes/install.core.inc
--- includes/install.core.inc	27 Nov 2010 04:43:08 -0000
+++ includes/install.core.inc	27 Nov 2010 19:02:41 -0000
@@ -870,7 +870,7 @@
     $form['driver']['#options'][$key] = $driver->name();
 
     $form['settings'][$key] = $driver->getFormOptions($database);
-    $form['settings'][$key]['#prefix'] = '<div class="js-hide">' . st('@driver_name settings', array('@driver_name' => $driver->name())) . '</div>';
+    $form['settings'][$key]['#prefix'] = '<h2 class="js-hide">' . st('@driver_name settings', array('@driver_name' => $driver->name())) . '</h2>';
     $form['settings'][$key]['#type'] = 'container';
     $form['settings'][$key]['#tree'] = TRUE;
     $form['settings'][$key]['advanced_options']['#parents'] = array($key);
@@ -905,12 +905,13 @@
   $driver = $form_state['values']['driver'];
   $database = $form_state['values'][$driver];
   $database['driver'] = $driver;
-  $form_state['storage']['database'] = $database;
 
   // TODO: remove when PIFR will be updated to use 'db_prefix' instead of
   // 'prefix' in the database settings form.
   $database['prefix'] = $database['db_prefix'];
+  unset($database['db_prefix']);
 
+  $form_state['storage']['database'] = $database;
   $errors = install_database_errors($database, $form_state['values']['settings_file']);
   foreach ($errors as $name => $message) {
     form_set_error($name, $message);
diff -u includes/database/sqlite/install.inc includes/database/sqlite/install.inc
--- includes/database/sqlite/install.inc	27 Nov 2010 04:43:11 -0000
+++ includes/database/sqlite/install.inc	27 Nov 2010 19:02:41 -0000
@@ -37,7 +37,8 @@
   }
 
   public function validateDatabaseSettings($database) {
-    $errors = array();
+    // Perform standard validation.
+    $errors = parent::validateDatabaseSettings($database);
 
     // Verify the database is writable.
     $db_directory = new SplFileInfo(dirname($database['database']));
@@ -45,11 +46,6 @@
       $errors[$database['driver'] . '][database'] = st('The directory you specified is not writable by the web server.');
     }
 
-    // Verify the table prefix.
-    if (!empty($database['prefix']) && is_string($database['prefix']) && !preg_match('/^[A-Za-z0-9_.]+$/', $database['prefix'])) {
-      $errors[$database['driver'] . '][advanced_options][db_prefix'] = st('The database table prefix you have entered, %prefix, is invalid. The table prefix can only contain alphanumeric characters, periods, or underscores.', array('%prefix' => $database['prefix']));
-    }
-
     return $errors;
   }
 }