> Why is "Ukraine fires on Poland, blames Russia" not news?

Because that's not what happened? That's spin. In fact Ukraine jumped on this story only once the AP published it. It's popular to attribute this to Ukrainian propaganda in some circles, but (heh, again getting to the actual subject at hand) that's not something you can report unless you can find evidence.

All the facts we know point to the Ukrainian government being just as fooled by the AP story as we were.