Plugin tests, which have dependency over the cash (AppletAttack for example) failed with ClassCastException on all platforms (WinXP, Solaris10, Linux9).
Same test working fine with latest promoted build.

To reproduce:
Enable JCP and execute plugin AppletAttack test from:
http://sqeweb/deployment1/deployment_tiger_exec_ws/deployment/tests/appletattack/pluginhtml-default/appletattack.html

Exception coming:

failed to load FactoryTest
java.lang.RuntimeException: java.lang.ClassCastException: java.lang.String
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
        at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(Unknown Source)
        at java.net.HttpURLConnection.getResponseCode(Unknown Source)
        at sun.applet.AppletClassLoader.getBytes(Unknown Source)
        at sun.applet.AppletClassLoader.access$100(Unknown Source)
        at sun.applet.AppletClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at sun.applet.AppletClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.applet.AppletClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClassInternal(Unknown Source)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Unknown Source)
        at SecurityTestApplet.init(SecurityTestApplet.java:67)
        at sun.applet.AppletPanel.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassCastException: java.lang.String
        at sun.net.www.protocol.http.HttpURLConnection.mapToMessageHeader(Unknown Source)
        at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
        at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
        ... 15 more

For full log got to:

file:/net/sqesvr-nfs/global/nfs/deployment3/tiger/PIT_builds/results/JD-PIT-56/plugin/winxp/pass_b56/logs/report_AppletAttack_log.txt