I'm not familiar with that detector as I use a CZ20 fisher and a minelab ex-cal 1000 for beach/water hunting but, I'd say "if you use any discrimination at all, set it to only take out the nails" and leave the rest so you don't miss any gold. You'll still dig lots of trash (but) it should skip over tiny nails, bobby pins, etc.
I know on most detectors, even on my fisher cz20, if I set it to discriminate #1 (which would probably be the same as your nail elimination) it will still pick up iron, and any gold rings, etc.
That's my take on it-
you may wanna do as the guy above said and, go thru and remove all the nails, junk, etc. and then you've got no worries as to finding that stuff anymore. It depends on how much junk, nails, etc. there is, and what you're mainly looking for. If there's tons of it, and you're looking for more jewelry than coins, I'd set the discrimination to the nail setting and hunt for a long while that way (like months) so you can clean up the ground quite a bit before using it with no disc. whatsoever.
Hope this helps a bit,
HH and show off your finds here!
Lonewolfe