When try to verify JDK-7181941, I find that mixcoded dialog still doesn't show up on Ubuntu 12.04 x64.

Steps to reproduce:
1) Install jre8 b121
2) Make sure Mixcode option "Enable - show warning if needed" is selected in JCP
3) Import the cert into signer CA.
http://sqeweb.us.oracle.com/deployment2/sheldon/webCases/javafx/MixedCode/tmpcert/self.valid.cert
4) Launch the applet from
http://sqeweb.us.oracle.com/deployment2/sheldon/webCases/javafx/MixedCode/html/MixedCodeApplet.html
5) After accepting Unsigned Security Warning and "Install Java Extension" dialog, the SSV dialog should be there. Now the applet just gets launched directly like "blocked" option is selected.

Note: On win7 x86, SSV dialog is able to show up using the same case.

Here are the related traces:
http://sqeweb.us.oracle.com/deployment2/sheldon/tmp/MixcodeTraces/

Observe java.lang.NoSuchMethodException: com.sun.deploy.ui.DialogTemplate.setMixedCodeContent(java.lang.String, boolean, java.lang.String, java.lang.String, java.lang.String, java.lang.String, boolean, boolean) in the trace.