Sorry this is so late, but I only noticed this now b/c a friend pointed it out to me (since I had this feature turned off). They discovered that when they tried to leave the first comment on an entry of mine with zero prior comments, using the inline-commenting tool (rather than loading the whole page with ?mode=reply), for some reason the comment box appears on the far side of my journal like so: http://i.imgur.com/JVP7j.png

This only happens on the first comment; after that everything is fine. I tested this as well after turning the beta feature on and got the same result. I suspect this might be in part b/c I am using a style that is ported from LJ, and maybe it's got something different in how it's written from the DW styles, and possibly this is not something DW is concerned with if that's why it's happening. But in case it happens with DW styles too or just so you know anyway, thought I'd mention it. :)