"I went out to a park here and decided to 'Costanza' my hunting technique. Nope, I decided I wasn't going to look for coins and rings but pull tabs and bottle caps. What an adventure, I did really well indeed."
Here's a novel approach, and one that has the potential for huge dividends. It boils down to shifting your mindset.
What you bought was a decent, basic detector. What I have started calling a "beep and dig" model, these days. I recall commenting when you first considered the Cib that you would have to learn it and it might not be easy. Seems I may have been right. Try to hear what it's telling you, as opposed to what you want to hear from it.
I know this is sorta out there as a post, but the uMax Tesoros, and especially the new breed, are indeed hot and iron can fool them. Here's what Pete has learned. If there's anyone who studies the dickens out of his tools, it's Pete:
"I did notice something neat and was wondering if other users could see if this duplicates for them. After detecting a questionable signal that is right on the border of breaking up and doesn't give you a perfect signal but still interesting. Pinpoint the target in disc mode. Mark the spot and pinpoint it in AM mode and see if the spot moves. I found that in every case where it did pinpoint differently but consistantly it was a crown cap. The pinpoint was out by about 1.5" to 2" with the 5.75 coil. The only penny that I found was the same spot in both modes, as were the square tabs."
This might also work for those pesky washers and other iron ghosts.
Also, try bringing your DISC to the mark below nickel and reducing your SENS a bit. Then let us know how that works.