From John Weber, Tue Apr 18 09:54:58 2006
The slowness of Quicktime on the instructor stations is because a previous Quicktime user viewed some files that have been removed from the system (possibly brought over on CD or other removable media), and Quicktime spends time trying to find them and then fails.
BEFORE clicking on a Quicktime presentation you should clear the list of unavailable items by launching Quicktime and:
Failing to uncheck this can cause long delays while attempts are made to download online media which is blocked by the firewall.
NOTE: If you are running a Power Point presentation with links to Quicktime movies you will need to start Quicktime before starting your presentation so that you can perform the steps above.