Working on an old Drupal 5 site (I was upgrading core), I came across a very odd bug. Every time I submitted a form, I was being redirected to the frontpage of the site. I had recently installed Path Auto and Global Redirect, so I thought one of those could be causing the problem.

With Global Redirect on, when I tried to visit a normal URL with an alias, in this case, node/2 that was aliased to services, I was also getting redirected to the home page.

Drupal's core "Path" module is a great way to rename a URL on your Drupal site to something more user-friendly. Instead of telling a potential client that your "services" page is at www.example.com/node/324, you can just tell them to go to example.com/services.