Unfortunatly due to a technical hitch it appears that any theme that uses custom 'block-regions' will not work correctly in Moodle 2.3.
However, to enable people to still use Aardvark Post-IT I have had to modify it so that it will work in Moodle 2.3.x albeit san moving blocks in the profile-bar. You can download the new version from the Moodle Themes directoy.
Here is a snapshot ofthe dropdown profilebar...inplace of the block regions I have added two postit-notes so you can add your own short messages to your students...
