Double entry in a track LB:
Coffee Break
It could be because the track was updated due to a SC (I notice that the track also appears twice in my "My Replays" list), but my two submitted times (with a new SC ...), appear one after the other in the LB.
[Edit] Just submitted a third replay, and that replaces the fastest of the other two, but still leaves the ealrliest submitted replay in second place. Hope that helps identify the bug/feature.