Why does the search module break cron I was trying to work out why cron wouldn't run on my site and came across this post: http://codekarate.com/blog/drupal-6-fixing-stuck-cron-run which said that enabling and disabling search would fix it. It did, but does anyone know why search breaks cron?
The Search module implements hook_cron(), and its implementation it invokes hook_update_index() to update the search index. One of that hook implementations is node_update_index(), which


Loads some nodes whose IDs are returned from a query
Renders those nodes, and passes their body content to search_index()


If the node body contains PHP code that redirects the users to a different page, or an implementation of hook_nodeapi() redirects the users when a node is viewed, that can cause problems to cron tasks.