I've had an after market amp installed along with new door speakers and subwoofer, however it's causing a slight problem.. it's having a delay in starting up. It powers up no problem(green light) but there's a delay before it actually plays through the newly amplified speakers. It'll only play the factory rears until it decides to start working properly, which can be a couple of seconds however lately it's been more irratic and staying off for 2-20 min and sometimes not coming on at all. The speaker wire is sending a very low signal into the amplifier.. anyone encountered this problem with their IS250 before?