Jason,I recently hunted an old abandoned farm.Using my XLT,I was scanning an area with 2" pickerbrush stubble.So my coil was 2" off the ground.I got a solid penny/dime id.Digging down 3",I recovered a rusty common nail.I rechecked the hole,still a solid penny/dime signal.digging down another inch,a square rusty nail!I told myself I'd check the hole one more time...surprise...still a solid signal,reading at 6".dug another 2" and up came a 1905 IH. Moral of the story...learn your machine,then trust it...but always check and recheck again!!!! I was wondering...when you found your square nail,did you check and recheck? HH-Steve