JSObject.eval() do not return when JDialog is opened.
Java version: jdk 6u12 build02 or later with new generation plugin enabled.
browser: Firefox 3.0.6, IE6, IE7 (not reproducible on Firefox 2.0)

To reproduce:
1. open attached TestApplet.html file in a web browser(it will run attached TestApplet.java).
2. click "run javascript button" - it will open JDialog and start a thread which opens
javascript alert window.

Expected results:
clicking OK button on javascript alert window should close
the JDialog windows and javascript alert window itself.

Actual results:
on jdk 6u12b01 or earlier (with new plugin enabled) (i.e. before a fix for 6764266)
javascript alert window freezes.

on jdk 6u12b02 or later (with new plugin enabled) (i.e. after a fix for 6764266)
javascript alert window closes but JSObject.eval() never returns and as a result
JDialog.setVisible(false) doesn't get called and JDialog window doesn't close.

Test case passes if an old generation plugin is enabled.

Attached is also original Oracle test case - OracleTestApplet.
After clicking OK on javascript aler window the whole browser
gets frozen. This is obviously because invisible (undecorated) modal JDialog
is still active.
Below is an explanation from Oracle why they need Javascript alert window
running in a separate thread:
"We had introduced this mechanism of setting a invisible JDialog to true
in our Forms code to fix another complex issue - bug 6802701. The problem
there was that when we execute javascript alerts in the Event thread, we
block the Forms client applet. If the applet is blocked beyond a certain
time, then the Forms server thinks that the client is already dead and thus
exits. To resolve this issue, we introduced the mechanism of running the
javascript in a separate thread and keep the forms client alive by running an
invisible JDialog. The advantage that we have here is that the state of Forms
would remain at the same point where the Javascript alert is brought up, but
at the same time keep the Forms client alive."