I also have marks left on my carpet from two slides in the living room area. They are dark skid marks is what it looks like. I think I saw somewhere on lippert's website that they have inserts to place there to prevent this. Sounds like a stop gap measure to me. I also noticed outside underneath the slide there is also beginning a serious scratch on the bottom side of the slide out. That could be a problem in the future. Got plenty of warranty left so may be taking this in to the dealer for their take on this.
2010 Jayco Quest G2(SOLD)
2014 Jayco Eagle 33.5RETS
2007 Ram 2500 5.9L Cummins(SOLD)
2015 Ram 2500 6.7L Cummins 4WD