I love mine. Yes it give weird readings and sounds, sometimes, usually when I try to get more out of it then I should or if I whip it to fast. The standard coin program with the threshold backed down to 18 is great and will produce coins in the 9 to 10 inch range all the time for me. Leave the fine tuning alone and see what happens. Gee the old Teknetics had the highest notes reserved for hot rocks so you learned to listen for the tones that were sweet music and not just the high ones. There will never be a machine that makes everyone do the happy dance, but I almost never bought this machine after reading the negative posts by a few people. That would have been my loss, big time. Last year I bought five new machines and I have 2 of them left. I just got rid of the ones that weren't for me. I was accused of bashing one manufacturer just because the machine broke down every three to four hours and I posted about it but I just got rid of it after the 3rd repair job in three months and swore never to buy from them again. It's a great machine and my personal thought is that no one has used one enough to know all the things that it can do.