Hello, I have two XD-V55 units rack mounted side by side. I notice that the one with the lapel mic goes from 100% signal to 0% and then then back to 100% randomly. It's as if the unit is searching for a better channel or something. It is never more than 30' away and has true line of sight. The last time it did it, I was literally ten feet away from the rack and it was doing it every couple minutes the entire time I used it. It has done this since I've had it (maybe a year and a half?). I only use it about 6 times per year but it is used for wedding ceremonies, so it's very embarrassing when the officiant is talking and it keeps cutting in and out. Of course everyone looks at me thinking I'm messing something up. I've been meaning to look into this for a long time, and I'm finally getting around to doing it. The one with the mic works fine. I also tested the TBP12 transmitter with a guitar cable to eliminate a mic issue, and it does the same thing. Any thoughts, ideas or suggestions?