Add me to the list. And for extra fun, the game doesn't even work, and I can't see the support form, so...
You should be able to register HttT and DW here at least. And the problem with the key will not prevent the game from launching.I also purchased EUIII: Chronicles through Steam recently and am experiencing the exact same problem with not only getting the game to launch, but with registering the CD key here as well.
I have the same exact problem. 2 DLCs were registered successfully but the game itself not. And yes, my product code starts with COMS too.