Mixers issues

Somehow I've accumulated 4 parts on my Mixer that are not on my score and which I don't want on my mixer. I've worked with this score for a couple of years and have made changes but have not added these parts. They don't show on the Parts list when I just show Parts. But they persist on my Mixer. I can't figure out how to delete them from my mixer. All the instructions to do so say to bring up the Parts list and delete them from there. I would like to get these partys off my Mixer. They dont show any activity when playing back. Can anybody help??

THANKS!!