Did you run all the scripts in update/common/scripts or only the one documented in the page http://ez.no/download/ez_publish/changelogs/ez_publish_3_8/upgrading for multilingual content :
I repeated the upgrade process with ezpublish 3.8.0rc1 and still I found the problem with the "User accounts" admin tab:
I logged OK in the admin siteaccess and clicked on the "User accounts" tab.
Under the left toolbar ("secondary menu") I view only the root node "Users" and no sub-items, but in the main area all sub-items are displayed (the standard groups). I executed only the exact steps provided in the upgrade instructions.