Originally Posted by Sprinkus
I've seen that happen with the probes in the ground but not ever with them out of the ground.
Usually what I do in that case is pinpoint the fault as best as possible with the wire locator, then check the spot with the fault finder receiver set pretty low. Pretty annoying to have the needle kick back and forth but if you watch closely you'll be able to see the "red" and "black" kick.
That is my guess also. Setting is too high.