I think that both steem power and steem are treated as one as they are always "converted" 1:1. So it probably stays where it is and just changes state. The only think I wonder is whether powered down steem is being calculated into the total steem power pool when assigning personal vote value. I will have to read about that.
EDIT: Just FYI the value of your voice is 0.027$, so you shouldn't worry. It just shows the two digits, but you will still get the correct amount.