When I run the 99 without thread, it runs like a champ 100% of the time. When I sew, 95% if the time I have no issue. The other 5%, it gets "stuck", or the feed dogs seem to stop advancing the fabric. I stop, remove thread from needle and give it a go that way...and there's nothing that appears wrong! I'm starting to think that either this machine doesn't like me, or that it's possessed. I guess that just gives me a reason to look for another, LOL.