There is a missing line in Tech Index on FF3 (okay in IE) between the old sticky and the new (bolded) unread post in thread listing:

This is minor, but since FF3 is new, it may be a sign of other things to come. I'm reporting it to Mozilla as well.

EDIT:

I doesn't seem to have anything to do with the dividing between stickies and regular threads or between new posts in thread and not. See: