WordPress 2.2.1 has been released, and it fixes some issues, both bugs and security issues that were present in 2.2.
Ryan posted the details over on WordPress’ blog:
WordPress 2.2.1 is now available. 2.2.1 is a bug fix release for the 2.2 series. Since 2.2 was released a month ago, the WordPress community has been improving fit-and-finish by identifying and fixing those little bugs that can be so annoying and by fine-tuning some small details. The result is a nicely polished 2.2.1 release.
Again, please remember that 2.2.1 is considered a required upgrade, as the security fixes are pretty huge.