Why am I afflicted with <div>?

[Auronlu]

I am puzzled by the appearance of a recurring tag at the end of my post which I'm not putting there. First I need to test to see when/where it occurs. If I just write a post --carefully avoiding any bbcode or odd stuff -- and hit Submit, Preview, or Go Advanced, I get this at the end of a post:
</div>

Edit: Aha!

I've isolated the problem, though I don't know why it happens. It happens in Default Editor Mode. If I click the A icon in the upper righthand corner of the editor to turn it from white to dimmed (plaintext, maybe?) I don't get the </div> tag.

 

[Bei Bei]

Well, I guess the problem is almost solved. I tried it out myself and I didn't get the problem you were having so I don't know why that happens