Not entirely sure if this is right, but just a thought--it's happened before that the map doesn't reset because of someone who logs on between rounds (i.e. between the time the next map is selected and everyone is sent back to the lobby) and then goes into the portal, loading the not-yet-reset'd map. Once I logged on right as 747 was picked and went immediately into the portal, unknowing that everyone was still in the last played map, and it loaded an un-reset 747 map with only me in it. When everyone, including me, was subsequently sent back to the lobby and went into the portals, 747 remained in its un-reset state.