Ok, so I got a logo that's made of group of compound paths with appearance, I've already Expanded it once, so appearances (strokes only) are separate paths, and what I'm doing next it taking all the objects from the whole document and expanding them so there's no appearances or anything that wouldn't act 100% accurate while scaling.
Then, something unexpected happened. (The image is from a small portion of a poster, containing an obvious problem.) It seems as if the outer path of the O in PARTIO wouldn be open ended, but it's not. Both, the inner and the outer path of the O are two anchored paths. BTW, tried "outline path" as well as Expand, didn't make any difference. It just breaks.
After a little bit of experimenting, I noticed that by adding third anchor point I can prevent the breaking, so I guess this is just a bug, and can't be helped, but can't be sure. I'll provide a picture here with the problem in detail and the workaround:
I applied the third anchor to all of the 3 shapes, approximately to the same point, and it worked wonders. Only thing is, what if I had a blend of 1000 steps, would I go all the way? Hmm.. not unless it paid really well ;).