I have a 2010 Nissan Versa, and I just swapped the factory stereo unit for a new one, a Dual XDM280BT. The new unit powers on fine, and the memory works, but no sound can be heard from it. That is, until I switch off the ignition. Then, for a split second, I can hear the sound before it goes away again. Can anyone help me out with this problem? I have no idea of what could cause this issue.