Ok, so you probably know about the WordPress 2.2 update and all the wonderful things WordPress 2.2 now introduces to your blog. One of those additions is WordPress widgets which are now standard. This poses a problem if you are using the K2 theme on your blog because there is an incompatibility between the K2 theme (with its widget functionality) and WordPress’ widget functionality. Basically what happens is that the blog goes “urk!” after you upgrade and doesn’t load much beyond the header.
There is a solution though. You need to install a plugin that disables WordPress’ widgets and which will then allow K2’s sidebar widgets to continue to function properly. You can get the plugin here. Install the plugin and activate it once you have performed your upgrade to WordPress 2.2 and your blog should work properly after that.
Just remember that when you upgrade to WordPress 2.2 to follow the instructions in the readme file. What I did was delete everything except my wp-content and wp-config.php file and upload the new files.