We have a Bissell Proheat

Question

We have a Bissell Proheat Cleanshot 2X Model 9500 Steam carpet cleaner. The first time we used it things were great. The second time we used it it left tracks in the carpet. We have no idea what caused this. We tried using the machine on an entirely different carpet and it did the same thing. After vacuuming the carpet about 10 or 12 times, the tracks are still embedded in the carpet - HELP!!!! We're read and reread the manual and contacted customer service and received no help.