poor radio reception

I have an Alpine 9845 receiver that I have had installed in a few different vehicles that I have had over the last couple of years, never had any reception issues with it, everything was great, but I bought a 2005 Nissan Pathfinder and after installation I have very poor FM reception, some stations come in but with low volume, other stations are very garbled, the factory radio works perfect.  I have pulled the radio out and checked the connection, made sure it was inserted solidly, and nothing seems to work for me.

Any help would be appreciated.

Thanks