I want to thank Ubelsteiner for his comments on uploading songs. Thanks to him, I was able to resolve two issues.
First, there is a critical bug where songs that don't have any downloads or views don't display anywhere. Of course, that's a problem because a song won't get any downloads or views without being displayed. This one is listed at
http://www.shoemakervillage.org/mantis/view.php?id=208.
Second, when a user uploads a song, its statistics will now be calculated immediately, rather than at the next hour. This seems to get around the issue of having to refresh all song calculations every time a song is uploaded, and addresses what shawnphase had called the "BS bug fix" (increasing the frequency of refreshes), which was the best solution I knew of at the time. This one is listed at
http://www.shoemakervillage.org/mantis/view.php?id=207.
Neither of these fixes have yet been released to production, but are available on the Dev server at svillage.mine.nu.
Feel free to offer comments and more reports as I continue to resolve other bugs.