I obviously used too much school glue...
Because my quilt is stiff in small spots and 2 of my machines refused to sew over them without skipping stitches. It was older glue - maybe 2 years old but a new container and it was Elmer's. I tried to FMQ using my Pfaff 6120 but it skipped. I tried a larger needle with no change, so I pulled out a Singer 15-91 figuring it would chew through the glue like butter. Nope. I used a size 14 needle and bumped it up to a 16 before I gave up on using the Singer.
As my last resort I pulled out my Pfaff 1222E. I put a size 14 needle in, dropped the dogs, and we were off to the races! I so love that machine. I don't know what I will do if anything happens to it. The Pfaff 6120 is a great machine too, but it doesn't have the oomph! of the 1222E.
I won't be using school glue again on a large project, I'll stick with spray basting. Whether it was user error (most likely) or the fault of the machines i used, I spent too much time I will never get back fooling with the results of the glue.