Safari 5.0.4 fixes a horde of security issues, improves stability
Safari 5.0.4 also brings a host of stability and compatibility improvements compared to its predecessors. Issues with stability when running multiple instances of plug-ins, compatibility with pages with image reflections and transition effects, printing with incorrect layouts, content display on pages with plug-ins, and the screen saver appearing while playing video in Safari, have all been fixed.
Safari 5.0.4 works on Mac OS X 10.5.8 or newer, as well as on Windows XP, Vista, or 7. The update has already been pushed through Apple's Software Update mechanism. You can also just download Safari 5.0.4 directly from Apple's website.