For those who have had trouble with your tension seeming to be "off" when you are trying to free motion quilt - I just read this in an online quilting newsletter.
If you have problems, do not drop your feeddogs - yes, you read it right! Leave the feed dogs up - then take a large sheet of teflon or plastic and tape it to your machine top, with a hole in it for the needle to go through - and it not only lets you move your quilt easier, your tension will return to where it is when your feeddogs are in place... the tension is released when the feeddogs are down! Seems like a simple fix to me - and it must be or it would not have been in print for tips from a mastered quilter.