If your sustain pedal has been inverted in Ableton Live you'll want to check these things:
- There may have been a slight glitch in Ableton, try restarting your computer and then opening the Ableton set again.
- It could be that the pedal was depressed when the keyboard was turned on. Try quitting Ableton, turning off the keyboard, and then turning the keyboard back on (making sure the pedal does not get pressed during startup). Then try loading the Ableton set again.
- The pedal may be inverted with that specific keyboard combination (some manufacturers design their pedals to function in the reverse manner, and their keyboard interprets the sustain signal correctly). You could try depressing the pedal, and then turning on the keyboard while keeping the pedal depressed.
- If that does not work, you might look into pedals that allow you to flip the polarity (like the M Audio SP-2).
Unfortunately there is no simple way to flip the polarity of the sustain pedal in Ableton, unless you look into Max for Live scripts.