On the upgrade from 1.8.2 to 1.8.13 the way /var/lib/moodle profile pics where handle changed in a subtle way. From users/x to user/0 user/1000 user/2000 this is a very good idea, but I can't find info about it on README.Debian or any other documentation, would be nice to add to the docs or/and ad a script to fix, as as moodle admin I just figure out today that all my users had the default happy face when not had uploaded their picture.