Problems updating to Date 2.6 with Date PopUp (date_popup)
If you are updating to Date 2.6 - then Date PopUp will need jQuery UI.
Once you update Date it will show this error
You will need to install jQuery UI.
If you don't have jQuery Update - to take your 6.1x Drupal install to jQuery 1.3 - then install jQuery UI 1.6 - otherwise install jQuery UI 1.7.
Use drush to download the jQuery UI project:
drush dl jquery_ui
Then download jQuery UI from Google Code.
Extract the zip file then rename the unzipped folder to jquery.ui.
Enable jQuery UI in admin/build/modules or Drush enable:
drush en jquery_ui

