Tomorrow is week 23 if you can believe it Cal!
Suzie have you tried using fun foam as your shim?
I have one particular large QuicKutz die that I could never get to cut in my cuttlebug and the only thing that has worked was using the regular sandwich for thin metal dies but putting a piece of fun foam between the cardstock I was cutting into and the cutting plate. Worked a treat and I never thought it would!
Fun foam is my last resort on any misbehaving die - thankfully only have two of them and not a whole load...