Each time I pull the USB from the top of the sensor out, I notice lots of moisture in and around the USB and the USB "holder" (including brown yucky stuff building up in there). I've been using a q-tip to soak up the moisture and clean the gunk. I make sure the connection is tight before monitoring any plant, to no avail. I live in Southern Louisiana, and I do have an irrigation system. The monitor has NOT been submerged, and the water is not directly hitting the monitor. Please - need suggestions as I love this thing, and do not want to waste the $$$ I spent on it.