This happened to me a few days ago when I reinstalled the game also. Should work once you've patched the game, but unlike what I did you could try to apply both patches 1.04 and 1.05 (I went straight for 1.05, which I suspect was a mistake).
Get patch 1.04 here:
http://files.bioware.com/dragonage/patch/1.04/DragonAge1.04.exe
and patch 1.05 here:
https://social.bioware.com/page/da-patches
If you have the DLC Witch Hunt you should download and install version 1.1 of that as well (link to it from the same "da-patches" page as above).
IMPORTANT!
If you're on a newer version of Windows (Win7 or higher) you may need to install DirectX9.0c manually (remember this is a game from the Win XP era!). It should be available on your physical game disks (if you've got those); otherwise get DX9 here:
http://www.microsoft.com/en-us/download/details.aspx?id=34429
Happy huntin'. :-)
