Rattle trap returns

Just some info for rattle trap users. I use rattle traps once in a while when searching for stripers in Marylands coastal bays and always get thrown off when I start seeing fish all over the screen with some even below the bottom line. Seems a rattle trap fools the sonar into marking fish when there are none. It only happens when fish ID is on and is usually when i realize that for some reason fish ID is on on my unit. Never noticed what it does when fish id is off. Any one else ever see this?