1BadPig, among the many things this item did to my radio, I also had the problem you are describing. This is indicative of your XM digital receiver going south. They replaced mine twice, the last time after I told them to take the PAL out. In addition, this thing seems to create power spikes. One precaution that GM told my mechanic to do was place a capacitor in the "power" wire to prevent this (GM sends the dealers to Radio Shack to acquire this item!!). This still didn't fix the other problems. Plus they are not sure the second receiver didn't go out after they did this. Also as noted on one of the other posts here, at first I could often get XM to work again after recycling through the channels (some times with as many as 12 presses of the channel button). Interestingly, GM is promoting the hell out of this accessory. Within two weeks of purchasing my HHR, GM sent me a post card promoting this (and other dealer-added accessories).