Ok so perhaps this isn't necessarily a bug, but I do see it as a usability issue (which I have reported usability issues in the tracker before, and they were actually sorted).

Basically the reason why you have to login to the AdminCP panel separately is because the session id has to be in the URL to prevent a hijacker from redirecting you to an ACP option with your active session (cookies was explored, but it was too risky).

I believe, however, usability for the administrator can be improved by pre-filling the email address into the login box and putting focus on the password box. That way all the admin has to do is put their password in. Or better yet add the session id into the url so they don't have to login again (although I'm not sure if there are any risks in doing this).

My issue is that I keep myself logged in to the forum, but I forget what email address I'm using. This happens especially when I am administrating different forums where I'm using a different email address.

If people want to speed up logging into the acp, every browser supports the ability to store login details. I don't think that's a decision we should make for people, personally.

I'd tend to agree.