I've had the same problem. The CM I spoke with suspected that my problem started when I created a user name on the family.com website a week ago. Apparetly that site's user name function is still in beta testing and he suspects that it corrupted the user ID and/or the password I use with the DVC site. Did anyone else recently create a user name on the family.com website?
They still haven't been able to fix my login, BTW. They say everything looks fine from their end, and their IT guys have confirmed that I'm using the correct user name and password, so they may need to completely reset my account (I'll be on the phone with them again tomorrow).
UPDATE: I tried logging in with the user name I created for the family.com website and it worked! It didn't a few days ago, but I'm in the site now.