Well, no, that's not what I meant, and I'm as quickly annoyed by that when I hear a channel drop, I usually pick up on it within seconds. Try listening to the beginning of Fairies Wear Boots with only the left or right channel, it's a completely different song. I know on my old Pioneer receivers, some of them have a mono button that just sums the two channels, and I know it's a rarity, but they still show up now and then.
But sounds like you already have most of it in place, so that was just to clarify.
Have you already sorted the short problem? I presume you did.