zed in damp soil or slightly salty ground

Hi, just wondering if any users of the 7000 have had experience yet with this machine in ground that is moist and ground that is moist with some salt rising out of it.
when we were in WA a couple years ago we could not detect ground with our 4500 and the same ground the previous year we had no trouble at all. When the ground was damp the machine just went haywire and it did not matter how you tuned it, turned down the gain or stabilizer it was just impossible.
we are hoping to get back there later this year again as was a good producing spot and with the rain they have had there so far this year is looking the same nondetectable area again. We  will be picking up our new zed tomorrow and are hoping that it may handle this ground a bit better.
also what would the machine be like on a salt lake?
any comments from zed owners?
thanks TG

moist ground did cause some stability issues with my zed, but only slight.

Moist ground should not bother it, unless the rain brought salt to the surface.