Apple has posted updates for both iTunes and QuickTime through the Software Update , bringing them respectively to versions 6.0.2 and 7.0.4.
iTunes release notes:
iTunes 6.0.2 includes stability and performance improvements over iTunes 6.0.1.
QuickTime release notes:
QuickTime 7.0.4 is an important release that delivers numerous bug fixes, support for iLife ‘06, and H.264 performance improvements. This update is highly recommended for all QuickTime 7 users.