We have seen clients with high cpu load caused by Java Quickstart Loader Cache. This will PRE Load Java Files when you Load Windows XP/2003 so when you start the app they will pull faster. Java Programm like Java VPN will generate a large amount of diskload with small files and the JQS will index those files. If you have a Virus protection behind that the Virus Proetction will follow up and scan those steps.
http://www.java.com/de/download/help/quickstarter.xml
“C:\Programme\Java\jre6\bin\jqs.exe“ -unregister “C:\Program Files\Java\jre6\bin\jqs.exe“ -unregister