It depends on the type of actuator exactly, but you could add rudimentary feedback relatively easily. Basically add some for of switch at each position, and that way you can reduce error by knowing you are at a location.
Without adding some form of feedback, this problem becomes more complicated and error prone. If you can rehome at 0 every so many changes (or whenever you get a new player), this problem is lessened. This also assumes the load on the actuator doesn't change versus position, (IE as you move further, gravity affects it more or less)