quoting ObsequiousNewt, Pixel:

I don't know if this has been reported yet, or if this is considered a bug (I'd rather not read through the past thirty pages), but the inline notes show up in the lower left corner of the browser window for me. (This is in Firefox 33.0 on Kubuntu 14.10) This is a problem largely because I can't see what the note says if it's linked to something, because the link location covers up the note.

That was a workaround for some issues when an inline note ended up on the right side of the render window, I believe. Not sure if it's unworkaroundable+I word! Nah no way I'm the first one to ever come up with this. or not.