Did you ever think that maybe your audio wasn't zero-bombed, but judged accordingly? I mean, think about it. Your audio had a 4.51 and a top spot on the page. When I stroll over to the AP, that's the kind of stuff I look for: high ranking audio on the first page. The majority of the time, when I listen to that music, I won't be as good as I expected it to be. I won't zero-bomb it, but I'll vote according. If I think it deserves a 2, I'll give it a 2.
I know a lot of people who frequent the AP who do the exact same thing, every day. They'll hang around the higher scoring audio, and listen to that. If they think it deserves a 2, they'll give it a 2. And with enough users voting accordingly like that, it's no surprise that your audio can fall off the front page easily.