Are you straight-line quilting or free motion quilting? If straight line, do use a walking foot to help the quilt sandwich feed evenly through. If you are FMQ, are you using the method where you leave your feed dogs up and setting the stitch length to zero? If so, it might be the fabric is slightly catching on the feed dogs. An easy fix for this is to punch a hole in the middle of a paper business card (or square of card stock or one of those pesky magazine renewal cards that are always falling out of every magazine) and tape it down on the bed of your machine with the hole over the needle hole. This will cover up your feed dogs and might make the glide smoother.. A Supreme Slider is great but expensive.