HeadSpace 3.6.21 has just been released and is in preparation for the upcoming WordPress 2.8, fixing several issues with tagging. In addition to this it also restores compatibility with WordPress 2.3 and 2.5. I’d be interested to know how many people are using older versions of WordPress (more than one major version) and whether this feature is of any use.
Also included in this version is a raw footer module that allows you to add anything to the wp_footer area of your theme.