K-7 broken? Erratic behavior.
Well, I don't have the K7 (have the K20 instead), and it doesn't sound like your problem, but you might just check that both e-dials are fully in their "detentes" and not stuck halfway between clicks. On the K20D (at least), if one dial is between clicks, the other dial won't work. Who knows what the affect on the K7 might be if the same thing happened. If nothing else, it's an easy thing to check/adjust.