We had an issue with a client that is using Google Apps for their email and when they went to their YouTube account, it told them that since Google bought Youtube, their Youtube account info needs to be merged with a Gmail/Google account. It suggested merging with his Google Apps account, which Google now treats just like any other Gmail account. Well, guess what? Google Apps accounts don’t support integration with Youtube, so if you link them up you get a lovely “This service is not available” message and you’re locked out of your YouTube account!
To fix it, you need to unlink your account which you can do here:
Then you can create a brand new Gmail/Google account here and then try to log in to your Youtube account using your OLD info and when it asks you to link the account with a Google Account make sure you link it to this new Gmail account – NOT your Google Apps account.