Its allways good to blame a PO for a mess your in. but in this case its true, I would have stuck to Lifecaulk,
I guess the 3M is just dooing what they said it would, Sorry 3M
Any way decided on cutting the whole mess out, I'll just use the old frames for a guide for my jigsaw, then I got a fresh new surface to work with.
Allways nice to have bigger windows anyway...