This issue is relevant when upgrading to Acquia Drupal because of the suite of modules included in the distribution's archive.
Problem: Although the Content Construction Kit (CCK) sub-modules are all dependent on the main Content module, Drupal 6's upgrade behavior does not currently take into account module dependencies. Some CCK sub-modules rely on the database being updated by the main Content module before they can run their upgrades.
Solution: If your site uses custom content types and CCK fields generated by certain CCK sub-modules included in the Acquia Drupal distribution (see below), remove all sub-module directories from the [acquia_tarball_path]/modules/acquia directory and place them completely outside of your [docroot] directory before running the update script. These are:
Move the sub-module directories back into the [acquia_tarball_path]/modules/acquia directory following a successful upgrade, then activate them on the modules page at Administer > Site building > Modules (?q=admin/build/modules) and run the update script again by navigating to http://example.com/update.php in the browser and following the instructions presented to you.