I just thought I would add that I reported this same problem originally in January and La Crosse blew me off multiple times. As the end of my 1-year warranty is coming up I complained again, and they had me go through the pour water in for 10-tips thing and send the results. They then replied and said to pack up the whole unit, display, sensors, and all and send it in to them. Once they get it they said they would send a WS-2812U-IT system in return, but they don't have any right now so it could be a few months. (They did say the 1-year warranty would start over.)
I saw that Costco had the WS-2812U-IT for ~$80 a few days ago so I might just go buy one of those and then have a complete spare system.