I have an Ace 300 with a Crossfire 2 supreme deep coil. It is a hot coil but it just will not pin point. However a friend with the same setup has no problem. I took it to the beach today for the first time and the black sand made it useless! I never have that problem with my Compus 77B or my Whites 600D. or any other detector. Could the coil be bad?