Mail - Reply All?

I've been experience some trouble lately with Mail. It's more of an annoyance.

Let's say I'm on an email with 4 people. I'm CC'ed on the email. When I hit Reply All, it puts my email address in the CC tab again. Which means, when I do reply to all, I'll get an email from myself with the reply I just sent to the others.

I'm confident it shouldn't be this way


Is this a bug? Any way to turn it off?