I just purchased an AT Pro 3 wks ago and have had approximately 7hrs of use. I have read the owner's manual and watched the video several times and feel that I have made some good progress in using the detector more efficiently (ie: better at differientiating btw bottle caps and good targets, as well as better at pinpointing). My big issue right now is to stop being fooled by aluminum cans which ring high and don't have the "low-high-low" sound when on "Iron audio" with 35 Iron discrimination and switching over from Std Zero to Pro Zero. Can you help me?