hildebrandtjane

I have a brand new singer heavy duty machine and it is working fine except when I try using the walking foot to quilt (I am a brand new quilter), I am getting little wrinkles as I would expect if I didn't have a walking foot. Now it could be me and the way I'm cutting, sewing etc. except for one thing. As I was trying to stitch in the ditch (I'll never get this one to work) I noticed that the walking foot was leaving a mark in the material itself. I have taken a pic of it and I think you can see what I mean. This mark does not rub out. Any ideas what is causing it? I'm having a problem uploading the picture I took. I will continue trying but to discribe it, it looks like a groove right next to the sewing line, about 1/4 of an inch wide.