I have an older brother that I use as a backup, I cover the feed dogs with duct tape, it is heavier and stays put.
You must have the pressure foot down to engage the bobbin thread, there is a way to adjust the tension on the pressure foot someplace on the machine. Back off the pressure slightly and you should be able to move the fabric.
My machine came with an darning foot, if yours did not, you can buy one cheaply, you really need it to do free motion.
here is a link to sew4less
http://www.sew4less.com/product/4096...for_model_info
Hope this helps.