Tarski 2.1.4 contains a vital compatibility fix for anyone upgrading to WordPress 2.6. If you’re planning on installing WordPress 2.6, install this update immediately, before you upgrade your WordPress installation. Following the upgrade guide is generally a good idea.
Always back up your files and database before running a WordPress or Tarski upgrade.
It appears that options are now being automatically unserialised, which means that when Tarski attempts to unserialise the already-unserialised tarski_options object, an error gets thrown which breaks a bunch of stuff. All of which means, upgrade now, or you might potentially lose your Tarski options.
Tarski 2.2 is still in production, and will add some nice functionality as well as some performance improvements and a fair bit of tidying. I’ve backported a couple of bug-fixes from 2.2 to 2.1.4, so you don’t have to wait for them.
Issues with this release should be posted on the forum.