Re Jerry being sick:
Jamie first heard something about that as a rumor, but it was never confirmed. I've mentioned it on more than one occasion as a theory for why his characters sounded strange in VMMCM -- but it is just that: a theory. It's known for certain that Jerry couldn't make it to Vancouver for the shoot, but whether he dubbed the voices or not is not certain. It's also been suggested that perhaps the recording equipment was just bad, but that would seem really odd since (as Secret Squirrel noted) dubbing is a fairly common practice, and we've never noticed any voice distortion before.
It would have helped if we could have heard Floyd (Jerry's most famous character) for comparison, but Floyd's only dialogue would have been in the Snoop Dogg scene, which was cut.
I don't think anyone's doubting that anyone's giving 100%. If Jerry was ill, or if the equipment was off, that's certainly not Jerry's fault. At any rate, I'm glad to hear he's still an active performer. We want him around as much as possible!