I changed my Adobe ID recently after I was informed that the data have been stolen somehow. I changed email and password.
A few weeks later now, I had to perform a reset of my ebook reader. In order to get it work I have to run a set-up procedure which asks me to log-in with my Adobe ID. I tried but it would not work with the new log-in data.
Now I checked Adobe Digital Editions (ADE 4.0.5.) version on my PC which indicates that the old log-in data are still valid. However, the program does not allow to change it. There is a drop down menu which exclusively shows the old email adress on top and below an empty field for entering the password. I have no option to change the upper field. If I try to use the little arrow next to my old email adress nothing happens.
I talked to the hotline of Adobe. They told me to deinstall ADE 4.0.5. and download ADE 3 again. I did but it has not changed anything.