I'm with Patrice on this one...I recently discovered that I have better luck using the walking foot when I'm piecing a block....don't have to deal with the stretching that happens at the end of my seams. It makes sense to me to leave it on and use it...my theory is "if it ain't broke, don't fix it".
Check out a previous thread on here and a solution from Patrice to get a 1/4" using your walking foot.
http://www.quiltingboard.com/posts/list/15/13214.page