I'm curious why you need this kalos.
A few years back I sent a PDF for publication, it was vector "line-art" (black only) with "Black" text - it should have been treated as a one colour (Black) print, but for some reason the file insisted on been treated as full colour at their end (or maybe it was their layout software that insisted on treating it so). I dont really have much experience in this field, and the person I was dealing with at the publishers didnt really seem to be much of an expert either. We narrowed it down to the text, but couldnt figure out why it was so (as said, it was simply black text). To be honest I cant remember what exactly our solution was, we converted the file to "greyscale"/Black in some manner.
So, anyways, just curious
Also, if there is a solution, I'll certainly have a go at checking some PDFs... out of cusiousity :p