When you grab the first public betas of the latest software, you may find a few new features that upset you — new ways of doing things, functionality that’s been changed or moved, and new default behaviors.

This is often true of browsers and especially true of Firefox.

The team behind Mozilla’s browser is constantly adding little enhancements and changes to the user interface, and not all of them are welcome. The tiny tweaks sometimes get in the way of beloved behaviors that have been around for years. Luckily, Firefox is engineered to allow you to undo those changes and otherwise customize the browser to your heart’s content.

Here’s our guide to customizing Firefox 3.6.