Ok, basically this is it: I work for a newspaper, and we do the printing for other smaller papers. (the paper I work for isn't really that big to begin with anyway). Another paper has a grayscale ad that they wanted to add some spot color to. When they did that, and sent it to us, it somehow printed with a screen over the whole ad of the spot color.
We've been working on it here, and we can get the spot to work, sorta. But the black is separating on all 4 plates, no matter how we work it, and no matter what color mode we use. We figure the ad was built wrong in the beginning, probably made in MS Word or something crappy like that. But I don't know where the ad originated to find that info out.
Sorry if this made no sense, lol.