WordPress released its latest package yesterday. It is recommended to upgrade your WordPress installation to the latest release.
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. (source )
This release also fixed some security vulnerabilities:
Okey, you’d better upgrade it.