why do duplicate entries happen?

I'm getting lots of duplicate entry errors in my log. some are ubercart errors, some are theme errors...

should I clean out the duplicates somehow?

I'm still pretty new to drupal, so any help is really appreciated!

here are a couple of the duplicate entry errors...

Duplicate entry 'admin/store/settings/countries/%/update/%' for key 1 query: INSERT INTO menu_router (path, load_functions, to_arg_functions, access_callback, access_arguments, page_callback, page_arguments, fit, number_parts, tab_parent, tab_root, title, title_callback, title_arguments, type, block_callback, description, position, weight, file) VALUES ('admin/store/settings/countries/%/update/%', 'a:2:{i:4;N;i:6;N;}', '', 'user_access', 'a:1:{i:0;s:16:\"administer store\";}', 'uc_country_update', 'a:2:{i:0;i:4;i:1;i:6;}', 122, 7, '', 'admin/store/settings/countries/%/update/%', 'Update a country', 't', '', 4, '', 'Update an installed country.', '', 0, 'modules/ubercart/uc_store/uc_store.admin.inc') in /home/content/g/l/a/glassshack/html/includes/menu.inc on line 2423.

Duplicate entry 'themes/garland/minnelli/minnelli.info' for key 1 query: INSERT INTO system (name, owner, info, type, filename, status, throttle, bootstrap) VALUES ('minnelli', 'themes/engines/phptemplate/phptemplate.engine', 'a:14:{s:4:\"name\";s:8:\"Minnelli\";s:11:\"description\";s:56:\"Tableless, recolorable, multi-column, fixed width theme.\";s:7:\"version\";s:4:\"6.11\";s:4:\"core\";s:3:\"6.x\";s:10:\"base theme\";s:7:\"garland\";s:11:\"stylesheets\";a:1:{s:3:\"all\";a:1:{s:12:\"minnelli.css\";s:36:\"themes/garland/minnelli/minnelli.css\";}}s:7:\"project\";s:6:\"drupal\";s:9:\"datestamp\";s:10:\"1241050838\";s:7:\"regions\";a:5:{s:4:\"left\";s:12:\"Left sidebar\";s:5:\"right\";s:13:\"Right sidebar\";s:7:\"content\";s:7:\"Content\";s:6:\"header\";s:6:\"Header\";s:6:\"footer\";s:6:\"Footer\";}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:7:\"scripts\";a:1:{s:9:\"script.js\";s:33:\"themes/garland/minnelli/script.js\";}s:10:\"screenshot\";s:38:\"themes/garland/minnelli/screenshot.png\";s:3:\"php\";s:5:\"4.3.5\";s:6:\"engine\";s:11:\"phptemplate\";}', 'theme', 'themes/garland/minnelli/minnelli.info', 0, 0, 0) in /home/content/g/l/a/glassshack/html/modules/system/system.module on line 821.

Duplicate entry 'sites/all/themes/pixture_reloaded/pixture_reloaded.info' for key 1 query: INSERT INTO system (name, owner, info, type, filename, status, throttle, bootstrap) VALUES ('pixture_reloaded', 'themes/engines/phptemplate/phptemplate.engine', 'a:13:{s:4:\"name\";s:16:\"Pixture Reloaded\";s:11:\"description\";s:166:\"Recolorable multi-column liquid/fixed layout theme. Original Design by Pixture Studio, Ported to CSS layout by <a href=\"http://adaptivethemes.com\">AdaptiveThemes</a>.\";s:7:\"version\";s:7:\"6.x-3.2\";s:4:\"core\";s:3:\"6.x\";s:6:\"engine\";s:11:\"phptemplate\";s:7:\"regions\";a:8:{s:6:\"header\";s:13:\"Header blocks\";s:9:\"superfish\";s:14:\"Superfish menu\";s:11:\"content_top\";s:11:\"Content top\";s:7:\"content\";s:7:\"Content\";s:14:\"content_bottom\";s:14:\"Content bottom\";s:4:\"left\";s:12:\"Sidebar left\";s:5:\"right\";s:13:\"Sidebar right\";s:6:\"footer\";s:6:\"footer\";}s:11:\"stylesheets\";a:1:{s:3:\"all\";a:2:{s:10:\"layout.css\";s:44:\"sites/all/themes/pixture_reloaded/layout.css\";s:9:\"style.css\";s:43:\"sites/all/themes/pixture_reloaded/style.css\";}}s:8:\"features\";a:9:{i:0;s:4:\"logo\";i:1;s:4:\"name\";i:2;s:6:\"slogan\";i:3;s:7:\"mission\";i:4;s:17:\"node_user_picture\";i:5;s:20:\"comment_user_picture\";i:6;s:6:\"search\";i:7;s:7:\"favicon\";i:8;s:13:\"primary_links\";}s:7:\"project\";s:16:\"pixture_reloaded\";s:9:\"datestamp\";s:10:\"1241716288\";s:7:\"scripts\";a:1:{s:9:\"script.js\";s:43:\"sites/all/themes/pixture_reloaded/script.js\";}s:10:\"screenshot\";s:48:\"sites/all/themes/pixture_reloaded/screenshot.png\";s:3:\"php\";s:5:\"4.3.5\";}', 'theme', 'sites/all/themes/pixture_reloaded/pixture_reloaded.info', 1, 0, 0) in /home/content/g/l/a/glassshack/html/modules/system/system.module on line 821.