As always I try to remind people of the hazards of updating Quicktime in mid-projects where things almost always go haywire.

Before you update your system be sure to read this sticky and save yourself from a potentially nasty pitfall if things go wrong after the update:

http://www.dvinfo.net/conf/non-linear-editing-mac/125182-how-update-your-os-apps-properly-save-your-system.html