Nightly: Signed applets are throwing security exception automatically after a while

Nightly build: Oct4
It has been noticed that signed applets are not waiting for user input on the security pop-up and after few seconds , they will end up throwing the security exception

Steps to reproduce:
1) Install Oct4 or latest nightly build
2) Try to load any signed applet or following signed applet
http://sqeweb.sfbay.sun.com/deployment1/deployment_6_UR_int_exec_ws/6/deployment/src/plugin/RSATestsuite/RSATestsuite/html/Thawtegrant.html
3) Security pop-up is going to be there. Wait for few seconds and after a while if java.security.AccessControlException is raised and security pop-up disappear then bug is reproduced