I have the same problem as jowwww. Everything else in ff works properly and as it should. After running the recommended tool, I agree that there is a corruption, though resetting ff and losing all addons, saved passwords, etc is extreme for one addon. Something in this addon has caused the corruption. I have the exact same problem across two computers in the same day. Both win10 and 64bit ff. I was really excited to finally find a replacement for Bamboo so I could finally update ff.

UPDATE: Just noticed note on main page to this addon concerning update. Sadly, I understand and will try reset.

UPDATE 2: Thank you to the developer for your response. I apologize for neglecting to read all the information you posted on the description page.