I have had a xterra 50 and now a xterra 70 and the buttons seem to go flat , especially the menue button where all the adjustments are made from. I sent the xterra 50 in and minelab sent me a new control head . Is the explorer and etrac equipped with the same type touch pad? I am very gentle when I depress any buttons on the xterra's. Has anyone experienced this and what did you do to fix it?