I called Kitchen Aid once after seeing black grease while using the food grinder attachment to grind beef. The black residue was in the meat. They told me that it was a food safe lubricant.

Aluminum will do that.

14:52 here - I'd wash them by hand from now on, as I try to avoid putting anything in the dishwasher that's not glass, stainless or ceramic. Try soaking them in equal parts boiling water and white vinegar. Let sit for an hour and then rinse. Repeat if necessary, or just use Barkeeper's Friend.

I put mine in the dishwasher all of the time. I have an older one, though...

Ummmm...yeah, but I was under the impression they were dishwasher safe (OK, my source was DH's aunt who gave me the mixer...). Crap! Is that the problem? Did I permanently ruin them?

Did you put them in the dishwasher?

The standard attachments to my mixer have gone "black." That is, they leave black marks all over my hands. When I attempt to wash them, they turn the rag black. Obviously, I can't use them for food! What went wrong?!?!?