I have a 08 mitsubishi evo x with a rockford fosgate system and just recently installed a Pioneer AVH-P4300DVD head unit, everything works perfect except when the weather gets warm outside the head unit mutes itself and the only way to get it off is to hold down source until the head unit shuts off then turn it back on but that only lasts for a little bit and then the mute comes right back. anyone run in to this problem before? any help is greatly appreciated!