Dts HD MA Sound Boom

[mastertang]

That's the best title I can imagine. Here's what I've got:
PS3 (60gb)
connected via HDMI to
Pioneer Elite VSX-81TXV

My PS3 is set to PCM all sound formats with no dynamic range control. During playback of DTSHDMA and even a few PCM titles, I hear a sound like a wooden bat hitting a piece of sheet metal. It occurs even when the sound is turned down low. It's a problem that only occurs during what I would call extreme sounds (gunshots, explosions, rockets, kung-fu punches).

I was hoping maybe someone had a similar experience and could offer some advice about how to remedy the situation. I understand the Pioneer VSX-81TXV has only a HDMI 1.2 capability, and I guess that could be a problem. Any input would be appreciated.