I had a month long penny wash. Apparently one of my Sensortrons crapped out and started to accept pennies. I tried to adjust the selectivity and nothing helped. So I replaced the coin acceptor with a new one. I cashed in 5 dimes, 669 pennies, and 1 very bent quarter. The Coinstar stole one of my bent quarters. I should have complained. I also got a gold neckless. That was 675 things that should have been quarters a $168.75 value (if they were quarters). I just need to check more often and I was stupid. But a good learning experience. Also took about two or three hours to sift through the quarter and pennies.
I use multitrons (tokens/quarters), and the same thing just happened- did replacing the acceptor fix the issue