Okay folks I have solved my issue and have this working now. Note this is for a Win7 PC version. I bought all of the DLC back in 2009/10 when I 1st played the game. After losing my disks and recently buying a new online download from Amazon I couldn't get my DLC to work. None of the solutions posted here and elsewhere on DLC known issues worked.
Instead, I used the manual process to install all of my DLC. 1st you download the DAZIP files of the content and then you use the daupdater tool to manually install it.
Here is a link with instructions on how to use the daupdater tool and links to download the DLC content DAZIP files. Make sure you download and install the DAZIP files for each DLC you purchased and NOTA BENE: for the quests there are 2 files! DLC file AND a corresponding OFFER file, get both. I had not done this at first and it was showing my content as enabled but the quests never triggered on the map. Items, like Blood Dragon Armor only have on file.
http://dragonage.wikia.com/wiki/Downloadable_content_(Origins)#Manual_installation
Hope this helps
