I'm learning Panels in Drupal 7 - with Presision theme as per
Youtube turorial: http://www.youtube.com/watch?v=8t58piu8HhQ&feature=relmfu.

I keep getting error message as below hen I try to save the design:
PDOException: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '77' for key 'PRIMARY': INSERT INTO {panels_pane} (pid, did, panel, type, subtype, shown, access, configuration, cache, style, css, extras, position, locks) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7, :db_insert_placeholder_8, :db_insert_placeholder_9, :db_insert_placeholder_10, :db_insert_placeholder_11, :db_insert_placeholder_12, :db_insert_placeholder_13); Array ( [:db_insert_placeholder_0] => 77 [:db_insert_placeholder_1] => 21 [:db_insert_placeholder_2] => right_region [:db_insert_placeholder_3] => entity_field [:db_insert_placeholder_4] => node:body [:db_insert_placeholder_5] => 1 [:db_insert_placeholder_6] => a:0:{} [:db_insert_placeholder_7] => a:9:{s:5:"label";s:5:"title";s:9:"formatter";s:12:"text_default";s:11:"delta_limit";i:0;s:12:"delta_offset";s:1:"0";s:14:"delta_reversed";b:0;s:18:"formatter_settings";a:0:{}s:7:"context";s:25:"argument_entity_id:node_1";s:14:"override_title";i:1;s:19:"override_title_text";s:9:"Something";} [:db_insert_placeholder_8] => a:0:{} [:db_insert_placeholder_9] => a:1:{s:8:"settings";N;} [:db_insert_placeholder_10] => a:0:{} [:db_insert_placeholder_11] => a:0:{} [:db_insert_placeholder_12] => 0 [:db_insert_placeholder_13] => a:0:{} ) in drupal_write_record() (line 7013 of /var/www/mysite/includes/common.inc).

It has me perplexed. I have viewed Brian Lewis's og ttu which has a section about panels but am still puzzled.
Google is unhelpful with  PDOException error messages.

Has anyone got some insight into this problem please
Thanks in advance
Roger