I need to set java.net.preferIPv4Stack=true to an app started via JNLP (javaws and applet)

Tried those, without luck...

```
<j2se ...java-vm-args="-Djava.net.preferIPv4Stack=true" />
<property name="java.net.preferIPv4Stack" value="true"/>
System.setProperty("java.net.preferIPv4Stack", "true");

```

The only way i could make it work was seeting when launching javaws from local filesystem:

```
javaws -J-Djava.net.preferIPv4Stack=true myapp.jnlp

```

What is not possible on a applet or URL.

How should i set this property?