One non-responding feed can make the entire moon page unavailable.
I'm not sure if this problem occurs only when the site has always been unavailable, or also when it was available and becomes unavailable.
This currently happened with http://audiores.uint8.com.ar/blog/index.php?tag=english&feed=rss2
Specifying a timeout in app/classes/Planet.class.php allowed me to see the moon again:
You can also stop the entire moon if there is an unescaped "&" (instead of "&") in the first feed.
The broken feed and all the feeds following the broken one will be ignored.
This set_timeout(-1) is in fact dangerous. If a feed is not reachable, for example the server where the feed is, does not respond, it leaves some opened connection in Apache, and after one hour or two, apache cannot respond at all on incoming requests, because two many connections are opens.
I commented this line.
Should be fixed by 8047a08