Funny you should ask...
I spray basted a whole slew of quilts a few weeks ago and they've been sitting here waiting for me to get to them ever since.
A couple of nights ago, I got my machine all cleaned and set up for FMQ, did a practice sandwich and it was sewing beautifully. Came up the next morning and started on one of the quilts - no go. Skipping stitches BADLY.
Changed the needle, re-threaded, changed the thread in bobbin and needle, removed the Sew Slip mat, put it back, changed the needle, changed the presser foot, adjusted the pressure up and down - skipped stitches.
But, I kept testing on the practice sandwich and the stitching was beautiful.
The adhesive in the quilt is still very sticky, though.
My last ditch attempt today was to iron the bejeebers out of it, but the adhesive is still very sticky. This prevents the needle from forming a loop for the hook to catch and create a stitch.
Next is to open up the quilt, remove the batting, cut out all the attempted stitching and baste it again. This time with the basting gun.
I took out a quilt with a fusible batt and I've been quilting it, instead. After all the frustration trying to get the sticky one quilted, it's a relief to be actually quilting again.
I'm not sure that I'll EVER use basting spray again. I still have five or six quilts basted with spray - I haven't had the heart to open them up and check them, but I think at least one of them is sticky enough to cause this same problem. :(