Now available via Software Update:
Security Update 2004-10-27 delivers a number of security enhancements and is recommended for all Macintosh users. This update includes the following component:
Apple Remote Desktop
For detailed information on this Update, please visit this website: http://www.info.apple.com/kbnum/n61798
This seems to be only for ARD users, only those with ARD client version 1.2.4, only for Mac OS X 10.3.n, and only a problem when fast user switching is enabled.
The iTunes 4.7 and Quicktime 6.5.2 updaters are also now available via Software Update.