This bug affects the WebDT Content Manager Version 3.0 (SP1 and SP2 included).
Symptom
If you are using the Combo List as the default playlist for a group and after you have updated the Combo List (Perhaps by changing one of the sub-playlists), the new Combo List will unfortunately not download/update to all players within this group. As a consequence you will still see the old combo list being played back.

Resolution
We have a patch for WCM3.0 to be installed on the server. Please enquire with signagesupport@dtri.com for the patch if you need one.