WordPress SEO by Yoast is a great plugin. The author took a  lot of functions and put them into one place.

But with version 0.2.1 the plugin has a bug that slows down posting  a lot. After digging through the plugin for an hour, i found the problem: this function in admin/class-metabox.php

function rebuild_sitemap( $post ) {
    global $wpseo_generate, $wpseo_echo;
    $wpseo_generate = true;
    $wpseo_echo = false;
    require_once WPSEO_PATH.’/sitemaps/xml-sitemap-class.php’;

Even if you are not using the sitemap functionality, that function goes at work. I’ve deleted the function, disabled the sitemap function from the plugin and started using another sitemap plugin.

Update: also delete this

// When permalink structure is changed, sitemap should be regenerated
add_action(‘permalink_structure_changed’, array(&$this,’rebuild_sitemap’) );
add_action(‘publish_post’, array(&$this,’rebuild_sitemap’) );