I have a z1 in my 2006 trailblazer that's about 4-4 1/2 yrs old and just recently (about a week or two ago) the left channel both front and rear will occasionally go out. Just some static and the right channel works fine. The other thing is that it is only with the XM and the iPod, library and disc work fine. I just thought it was strange that it was only happening with certain sources and not others. I did try a reset when the problem was occurring with no luck. Same issue immediately following the reset. Anyone else ever run into this? Any help is greatly appreciated