Sewing Machine Troubles

My sewing machines are not cooperating...

I went to our guild's sew-in today to make pillowcases for philanthropy.  I had made 12 pillowcase kits - using up some of my inherited stash.  They're old-fashioned but I think they're pretty.  I sewed 3 pillowcases at the sew-in, but it was hard going.  My baby-lock gathers, and I had to stretch the fabric seam as I sewed.  Very frustrating.  I adjusted the tension up then down but nothing seemed to help.  I  will take it to San Juan Capistrano to a fix-it shop down there that I've used.  Janet was making a zipper bag, and said she would help me on the next sew-in.

I did make 2 of Mickey's octagon mug rugs.  I used some of my new internet-bought fabric.  I even machine quilted a little in the center.  I also started machine quilting the witch quilt (at 2 am), and the Bernina's tension is off there.  I'm using invisible thread on the top and black in the bobbin, and the black shows as dots on the top!  I again tried adjusting the tension up and down but nothing helped there either.  The backing is black, so I need to match it.  I'll delay doing more work on it until I figure it out.

I need to find out and fix both machines.  In the meantime, I can sew on the Bernina I think.  The problem is using the invisible thread.  I will choose fabric for the 'Bloom' challenge quilt.  I should be able to make the blocks and decide how they're configured.