The last/first stitch is often loose. Try to do what people suggested in the other post about this. Also, make sure that when you're knitting that first stitch that you're not pulling it so your knitting into the bottom of it. If it gets wrapped around the needle, it looks like two stitches there.
One thing you can do is to just slip the first stitch of each row. That will tighten them up some as you work.