Dave Smith Instruments SYNTHESIZERS

Ben,
I had some similar issues with setting up sustain pedal for my PEK, but
here's what I did: turned on the PEK, plugged in the pedal. Notes held until
pedal was depressed. Flip polarity in the menu and it worked. I know that's
pretty much what you're doing, but for me, I had to keep flipping that
polarity plus to minus and back several times before it would kick in.
However, once it did, I've never had to set it again, so hopefully that'll
work for you. Good luck.
-Mark