This CR is filed to track the potential backward compatibility issue in Plugin2 after secure properties check feather is implemented.
In the new plugin2, any insecure system properties and java arguments in deployment.properties required applets to be signed. This is true on both vista and non-vista platforms. On vista platform, deployment.properties file is in a low integrity location. So it is untrusted by default. On non-vista platform, this creates incompatibility issue with classic java plugin. In the old plugin, unsigned applets can still run.
We may have to rethink the current implementation if the compatibility impact is significant.