Out of phase?

New home. Old stereo. My rig is sounding like crap, so I threw in the second Stereophile test CD. On the phase test, "The Fender bass guitar you are about to hear ...", it's all backwards. There is a central image when there isn't supposed to be one and vice-versa. All the connections have been checked and rechecked and then checked again. Speakers -- and all else -- wired up correctly. Any thoughts about what could be causing this? It's a really asymetrical room, with an open stairway on one side and a lost up above on the other. Is that what this is likely all about? If so, what does one do about a particularly odd space? (Short of moving, that is. I just bought this place.) Thanks. -- Howard