OK, here is how I am setting up to do these grooves (that gave the problem) I do use the under table as well and of course don't have the problem.
Got a little burn in the beginning and you can see where it went through a knot (on purpose

) didn't slip and cut a perfect groove :/

- router setup 04.jpg (342.75 KiB) Viewed 2032 times
Other pictures

- router setup 03.jpg (317.01 KiB) Viewed 2032 times

- router setup 05.jpg (344.58 KiB) Viewed 2032 times

- router setup 06.jpg (344.39 KiB) Viewed 2032 times
Cutting a groove with a 3 blade slot cutter (1/4 inch) and the shaper fence

- router setup 02.jpg (329.37 KiB) Viewed 2032 times
Do these look correct, any glaring setup errors?
And FWIW, the headstock didn't slip and felt pretty good going through the knot (of course)
Soooo this is what I am going to do. I will build a "stand" that will support this monster of a headstock to stabilize it on critical work (or any work for that matter). The over table system works perfectly most of the time, but sometimes it just doesn't. A stand with prevent me from over tightening the lock, and give me confidence that the cut will be true. Not that big of a deal in the general scope of things.
I am open to critique and suggestions if anyone sees need for improvement.
Thanks all for responding!
