Finishing link entry with enter sends the post instead
I just got caught by something I consider a bug: I wanted to link to a web site, and used the link button above the entry box to do so. After I finished entering (or rather, pasting) the link into the pop-up box, I pressed enter to get it into the post.
To my great surprise, this didn't cause the link to be inserted into the post, but instead it caused the unfinished post to be posted to the site.
This is highly unintuitive behaviour which I don't believe was intended.