I believe I've found a small bug in Movable Type, or more specifically the remember me part of commenting.

Here are the steps to reproduce.

1. Type your name and URL but no email in a comment box which requires the name, email and URL.

2. Check the remember info radio button or checkbox.

3. It will then display an error stating that the email address is missing.

4. Fill in your email address and hit post again.

5. Return to the comment page and the comments only display your name and URL, not your email address.

I guess it could have been on purpose, but it was unexpected when it happened to me.

I presume this is because the cookie gets set on the first page, not on the error page. So the information has been stored in the cookie already by the time the error page is processed.

I would guess that you could just add the JS for the cookie to the Comments Error Template?