I posted this same question a while back:
http://www.quiltingboard.com/t-115221-1.htm
I have automatic tension on my Babylock. I noticed also with the 1/4" foot with the guide that it seamed like the feeddogs were pushing the fabric to the left. Very wonky lines!
I was sewing 2 1/2" strips together and even with gently
holding the fabric straight behind the machine it still pushed the fabric to the left.
I just use the regular sewing foot and take my time and make sure I have an accurate 1/4" seam and evenly guide the fabric through.