The tire sensors have to be taught to the car for it to know which one is which. It appears that your tires were rotated without this being re-done.
Who rotated your tires? There is a procedure that you can follow to reteach them yourself, but if someone else did the rotation I would go back and make them do it.
Or you can leave them as they are. It doesn't actually hurt anything beyond not knowing which is low. Since I still check them manually with a tire gauge it wouldn't bother me.
Sky NA 2007 Midnight Blue
Sky RL 2008 Carbon Flash - Naked