Why are new versions of my plugin not becoming available for download?

The WordPress Plugin Directory seems to be scanning my plugin’s directory just fine but it is not making a new download for my stable tags. What am I doing wrong?

Here is the readme file located in my 0.3 tag:

http://plugins.trac.wordpress.org/browser/embed-github-gist/tags/0.3/readme.txt

Here is the readme file located in my trunk:

http://plugins.trac.wordpress.org/browser/embed-github-gist/trunk/readme.txt

They are both identical. They both have “Stable tag: 0.3” listed. Yet the only download that is created is my 0.1 download.

I had this problem with my 0.2 tag, created last night, and I created another 0.3 today again with no changes to see if it was just something odd with the scanner. It looks like whatever is wrong wasn’t just a temporary glitch with my 0.2 tag.