Many albums will only show the first X tracks (6 in my case) and you can expand the album to show the rest. If you double-click the album art without expanding the track list, only the displayed tracks are queued. If you expand the list and then double-click, all tracks are queued. This is definitely new in 3.0, as I just upgraded today and this is the first time I've seen it.
UPDATE: As we've discovered, this only happens with the last album in a list.
Avoid infestation. Rotate.