I am and fairly new at this quilting, and I am working on a queen, I had this problem too, I would pin and pin below my 1/4" line and the top, press in opposite directions and nuzzle my fabric together, still nothing would line up properly for me..I finally fiquired out it was the pressure on my presser foot that was to tight, it would push the fabric and create a mess, even with a walking 1/4" foot...dicovered this only by accident - I had loosened it to applique and didn't put it back. This is the first time every one of my seams, and corners all match! I am so excited! So, if all else fails, maybe try loosen or lighten, your pressure a little...have fun!