This is what happens when you change e-mail addresses
I have a few e-mail addresses I use. One primary (on this site, see contact area,) and for other sites I have to "sign up" for something I use the others.
I had to change my e-mail address on a message board on another site, and now my account got disabled - just because the address changed.
Usually, you'll get some kind of confirmation notice when you change an address. I didn't.
[-- edit --]
Got the confirmation mail. Took a really long time to get it, though. What can I say, I'm impatient. 😉