Safari browser for Leopard, Tiger, and Windows has been updated to version 3.2.1. The only note about the changes is "This update includes stability improvements and is recommended for all Safari users." This update comes only 12 days after 3.2 was released, so good for Apple on keeping up even with the smaller bugs!
From a quick look around the web, it looks like the probable cause is do to some incompatibility with third party software that was causing Safari to crash for many users, which should be fixed now.