Wow. I had this so very, very wrong. In addition to the cables crossing the wrong way and the selvage stitches only making occasional appearances, I had the cable length wrong. I was crossing them every twelve or fourteen rows, depending on how badly I was screwing up. It's supposed to be every TEN rows. I thought they looked too rectangular, but continued on without looking at the pattern for some reason.
Restarting was as good move.