In case you want to upgrade to magento 1.4, and have Yoast MetaRobots installed, you'll have to uninstall it first, since it's not compatible with 1.4.
Here's how:
1. uninstall it from magento connect
2. Remove the config xml file from /app/etc/modules/Yoast_Metarobots.xml
3. Remove the module files and directories from /app/code/community/yoast/Metarobots/
4.Clear your cache
SSH into your root magento directory and:
rm -rf var/cache/*5. run this SQL query (easily done in phpMyAdmin)
DELETE FROM `eav_attribute` WHERE `eav_attribute`.`attribute_code` = 'meta_robots';
DELETE FROM `core_resource` WHERE CODE = 'metarobots_setup';You should be good to go after this...