Very new to the V3i. Searching an old park today. Occasionally, I'd get a fairly good signal swinging left and right but when I would pull the trigger to go in pinpoint mode, I'd find nothing in the area I was scanning. This happened on several targets. Other targets it would work fine. I never dug any of the silent pinpoints so naturally I didn't get to find out if there was anything really there. I was able to verify the Pinpointer function was working at the same time I was getting mystery silence by using a known metal target so I I don't think for a second that the switch or pinpoint mode were not working. Any ideas?