Skipped stitches when FMQing is usually due the needle bending as you move the quilt. Slow down a little and give the needle a chance to do its job. The needle is not coming out of the fabric all the way before it gets moved to the next stitch This causes the needle to flex and miss contact with the hook just enough to cause a skip. Try using a top stitch or metallic needle.
Hope this helps.
peace
EDIT: Try the simplest and easiest things first before having it seviced. If all these tips fail then take it in.
Last edited by ube quilting; 07-05-2013 at 09:53 AM.