I built a double track oval using the Bachmann Ez-Track Left and Right Remote Crossovers (44575 and 44576).  I applied DC power to only the outside track, but I also have power on the inside track.  I assume that the power is flowing through the crossovers from the outside track to the inside track.  How do I isolate the crossovers so that each track can be powered seperately, but the trains can travel over the crossovers between the two tracks and not loose power on the crossover.