Error messages

I've just gone to the Admin page of one of the set of sites running on a common codebase of Drupal 6.9 code and gotten a whole set of messages like that below. What does this mean and what do I do about it?

user warning: Duplicate entry 'themes/tapestry/tapestry.info' for key 1 query: INSERT INTO system (name, owner, info, type, filename, status, throttle, bootstrap) VALUES ('tapestry', 'themes/engines/phptemplate/phptemplate.engine', 'a:13:{s:4:\"name\";s:8:\"Tapestry\";s:11:\"description\";s:31:\"A Drupal 6 theme by RoopleTheme\";s:4:\"core\";s:3:\"6.x\";s:6:\"engine\";s:11:\"phptemplate\";s:7:\"regions\";a:31:{s:11:\"leaderboard\";s:11:\"Leaderboard\";s:10:\"suckerfish\";s:15:\"Suckerfish Menu\";s:12:\"sidebar_left\";s:12:\"Left Sidebar\";s:13:\"sidebar_right\";s:13:\"Right Sidebar\";s:15:\"sidebar_outside\";s:15:\"Outside Sidebar\";s:16:\"content_top_left\";s:16:\"Content Top Left\";s:17:\"content_top_right\";s:17:\"Content Top Right\";s:19:\"content_bottom_left\";s:19:\"Content Bottom Left\";s:20:\"content_bottom_right\";s:20:\"Content Bottom Right\";s:11:\"header_left\";s:6:\"Header\";s:13:\"header_center\";s:6:\"Header\";s:12:\"header_right\";s:6:\"Header\";s:6:\"banner\";s:6:\"Banner\";s:5:\"user1\";s:6:\"User 1\";s:5:\"user2\";s:6:\"User 2\";s:5:\"user3\";s:6:\"User 3\";s:5:\"user4\";s:6:\"User 4\";s:5:\"user5\";s:6:\"User 5\";s:5:\"user6\";s:6:\"User 6\";s:5:\"user7\";s:6:\"User 7\";s:5:\"user8\";s:6:\"User 8\";s:5:\"user9\";s:6:\"User 9\";s:6:\"user10\";s:7:\"User 10\";s:6:\"user11\";s:7:\"User 11\";s:6:\"user12\";s:7:\"User 12\";s:6:\"user13\";s:7:\"User 13\";s:6:\"user14\";s:7:\"User 14\";s:6:\"user15\";s:7:\"User 15\";s:11:\"footer_left\";s:11:\"Footer Left\";s:13:\"footer_center\";s:13:\"Footer Center\";s:12:\"footer_right\";s:12:\"Footer Right\";}s:7:\"version\";s:11:\"6.x-1.x-dev\";s:7:\"project\";s:8:\"tapestry\";s:9:\"datestamp\";s:10:\"1207915839\";s:8:\"features\";a:10:{i:0;s:20:\"comment_user_picture\";i:1;s:7:\"favicon\";i:2;s:7:\"mission\";i:3;s:4:\"logo\";i:4;s:4:\"name\";i:5;s:17:\"node_user_picture\";i:6;s:6:\"search\";i:7;s:6:\"slogan\";i:8;s:13:\"primary_links\";i:9;s:15:\"secondary_links\";}s:11:\"stylesheets\";a:1:{s:3:\"all\";a:1:{s:9:\"style.css\";s:25:\"themes/tapestry/style.css\";}}s:7:\"scripts\";a:1:{s:9:\"script.js\";s:25:\"themes/tapestry/script.js\";}s:10:\"screenshot\";s:30:\"themes/tapestry/screenshot.png\";s:3:\"php\";s:5:\"4.3.5\";}', 'theme', 'themes/tapestry/tapestry.info', 0, 0, 0) in /var/www/bin/drupal-6.9/modules/system/system.module on line 821.