Audio drop out in front center speaker

[scoob958]

I have the Yamaha RX-V465. When I get to a particularly loud and intense scene in a movie the sound in the center speaker drops really low so you can't hear the dialog all you can hear is whatever is coming out of the other 4 surround speakers. The helicopter chase scene from Wolverine was a prime example of a movie I had this problem on over the weekend. Once that scene ended the sound was fine again. Anyone know what the problem is I could be having? It did it during one scene in Whip It last night as well. But only momentarily as that movie really isn't that loud and intense.

Thanks