A number of system properties were added to the "secure" list in Mustang (see 6250769),
however it appears that the Java Web Start Developers Guide was not updated
accordingly. I would expect to see these new system properties listed here:
  http://java.sun.com/javase/6/docs/technotes/guides/javaws/developersguide/syntax.html

This has led to developer confusion about which flags are considered secure, as in
the following thread:
  http://www.javagaming.org/forums/index.php?topic=14092.0
so we should fix this for Mustang to reduce that confusion.
I fixed this bug with the latest secure tags and vm args information.

- Jacob Royal