A couple of days ago I've drawn a few buildings (e.g. way osm.org/browse/way/119774654) close to another in a block, in a changeset 8591706, which contains many other buildings and sidewalks and tracks - yet just especially these 5 buildings' corners are highlighted with thick red circles whenever displayed in Potlatch2 editor.

Some buildings' ways share their nodes, but many nodes are used just once and one building is completely separated. I've tried to find out (checking the ways' nodes, using KeepRight (http://keepright.ipax.at/report_map.php), trac, wiki, etc.) the reason, but found nothing. Such circles can be occasionally seen around.

Does anyone know the reason?

OK, my first complaint :-) in osm.org/user/kerosin/diary/14153 and immediately followed by Ticket #3836 (see http://trac.openstreetmap.org/ticket/3836) - I've already lost at least some 6-7 hours of work this week...