Sometimes skipping stitches is because of the needle. Did you put a new needle in? The needle also has to be the right size for the project. I piece with a size 11 needle but I quilt with a 14, especially when sewing the binding on. I generally use a 40 or 50 weight thread for piecing and a 30 or 40 weight thread for quilting. Matching the thread to the needle is very important in getting a good stitch.
Pam