I'm using WinXP/Chrome, this didn't happen before. I click "Edit" on an existing comment, either on the comments list ( http://lesswrong.com/r/discussion/comments/ ) on on the comment's permalink page ( http://lesswrong.com/r/discussion/lw/d3h/open_thread_june_1630_2012/6wr3 ). What I see in the edit area is 3 newlines, followed by comment's text, followed by 3 more newlines. For another comment ( http://lesswrong.com/lw/d5s/new_singularityorg/6uwn ), it's just one newline before the comment's text and one after.

These newlines don't display outside editing areas, I didn't put them there, and they are not just presentation artefact, since cursor moves through them and if I add a line after them, the resulting display takes them into account.

Also, after I deleted these newlines (in the first comment), they didn't come back in the same editor, but one newline came back after I re-opened the comment in a new tab.

I experimented a bit more, and the rule appears to be that each edit automatically adds a newline pair to a comment, one newline at the start, and one in the end. Multiple edits that don't involve deletion of these newlines result in multiple newlines at the start and at the end of a comment.

I expect this is a result of the changes made in #304

Pull request sent - https://github.com/tricycle/lesswrong/pull/23

This has been merged and deployed.