JDK 6u18 b02 doesnt fix bug 6783619 as it says in the Rel. Notes (nor b01)
I read in JDK6u18b02 that bug id 6783619 at java_plugin:plugin2 has been fixed.
The bug description is: showDocument calls result in the new browser window opening behind the current top window.
I have tested it using b01 and b02 and the problem is still there
Comments have been addded to bug: 6783619 also and there are code samples to test and reproduce in duplicate bugs: 6776124 and 6780276.
Please, don't consider this bug closed yet for u18 and later