Lines are missing between feed items in the Formal White theme (see attached graphic). I noticed that other themes also have this problem. The "Standard" theme does include lines, which is why I am reporting this as a "bug".

I suggest that the line be the same with as those between topics (see graphic). The line that is used to separate Upcoming Events might be too wide.

I had already created a more general tracker item MDL-28561 (see attachment), which was "moved" to a theme problem. Then, in MDL-29211, it was suggested that I start a new tracker item so that this line issue could be added to the similar line issue about forum posts.