With over a million downloads of WordPress 2.9, WordPress 2.9.1 has been released to address some technical issues and bugs which caused problems with scheduling of posts and pingbacks. Unless you’re not experiencing other issues, there’s no need to upgrade, but before doing such upgrade be sure to back up first your database and other WordPress files to be safe, (keep your fingers crossed.. )
For those who have previously upgraded to WordPress 2.9 here are the new features you can try to visit it’s worth the read!.
Download WordPress 2.9.1 or you can use the automatic update feature within your WordPress admin Dashboard. Happy Blogging!