I found this on another site and it worked for me:
I have really been bothered by having to watch ABC shows online through a tunnel, which as of my most recent discovery was pointless. The problem isn’t with comcast filtering, there is some sort of problem with the ad system they have setup. Some of the ABC affiliates don’t work correctly and cause the shows to never start playing resulting in either a black screen or the waiting cursor circling round and round.
Assumming you have no other problems
, open a new browser window or tab and enter the following URL.
That’s it, you should now be able to watch all the ABC.com online shows. The only difference is the &aff=kjif at the end. Enjoy.