I just tried to book on-line and got a "down for maintenance" notice.
I wasn't having issues earlier, but I am now. It tells me I am entering the incorrect password, but I know I'm not. I made sure I was logged off disneyworld.com, but it still is saying that. I'll give it some time to reset itself, hopefully.
I've just tried to access dvcmember.com from the UK just now and it is telling me that I have entered an incorrect user name / password and like the abover post, I know I have entered the correct details.
David
If attempting to use an iPad and Safari, there have been reported problems like the one you mention; likewise sometimes for using Safari on a Mac computer. If that is what you are using try Chrome (App download) on either. If that is not the issue, you might just have an issue going on with your particular computer and may need to do something like try a different browser or empty your cache.