My Vista system has both 6u7 and 6u10 JREs. I disabled 6u10 from the java control box(customers would do that just to try out the latest JRE but most of time disable it).
I tried the following link both FF3.03 and IE7.

http://sqeweb.sfbay.sun.com/nfs/testbase/sqe/javafx/animation/browser_tests/b43/FxQuizApp/FxQuizApp.html
It was packaged by b43 javafxpackager.

A security warning box will appear with the message,
The application requires an earlier version of Java. Do you want to continue?
[Run][Cancel]

Now press Cancel button.
The problem is that it doesn't cancel and continuously showing the same security box.
At the end, I press "Run" then close the browser.
Logged from
http://openjfx.java.sun.com/jira/browse/RT-1556