you need to make sure that if you are doing garter stitch (knit every row) that you are pulling your yarn under and behind the needle when you start the row. If it is up and behind it is giving you what looks like an extra stitch there on the needle. when you get to the end of your row, pull the yarn both ways so you can see the difference. under and behind is what you want. if you go up and behind it creates a "yarn over" which will increase your stitches.