Our XL4 has been working flawlessly for the past 4 months and this morning decided that tuner 4 would lay down and die on me. Has anyone else had this happen? I went through the diagnostics and found tuners 0, 1 and 2 were all working with signal strengths of 92-98 though out the channel spectrum. Tuner 3 shows a constant signal strength of 0. In fact, it shows a dash mark where an actual strength number should be. Are tuner issues common with the new XL4s? I've really enjoyed having 4 tuners. I haven't had to deal with any conflicts between family members!