JFileUpload and all add-ons support Java 1.6 update 10.
Under Vista Java 1.6 update 10 (or higher) is recommended. The JavaScript that comes with JFileUpload (and its add-ons) could be modified to make sure that end-user will be redirected to the correct 1.6 download page from SUN when Java is not installed. To do so, make a search/replace in the .js file with:
1/ Codebase:
Search:
codebase="http://java.sun.com/update/1.4.2/jinsta ... on=1,4,0,0">
And replace by:
codebase="http://java.sun.com/update/1.6.0/jinsta ... n=6,0,0,33">
2/ Type:
Search all occurrences of:
application/x-java-applet;version=1.4
And replace by:
application/x-java-applet;version=1.6