Spike

On the 20th of April, the “Java Deployment Toolkit 6.0.180.7″ has been Disabled by Mozilla Firefox due to stability and security problem.
At the bottom you can read:
Java Deployment Toolkit, versions 6.0.200.0 and older. Reason: security vulnerabilities (see bug 558584).

If you want to remove it from the plugin list, close Mozilla Firefox, go to

C:\Program Files\Mozilla Firefox\plugins\

and remove npdeploytk.dll.
Now you can go to http://www.java.com/en/download/index.jsp and download Version 6 Update 20.

This extension is installed by Nokia PC Suite. The problem is that the uninstall button is greyed out and even if you go into Firefox safe mode you still can’t uninstall it.
So you can remove it by going here

Start>Run>Regedit>HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Firefox\Extensions

and delete the key named

bkmrksync@nokia.com

on the right.

If you want also to remove “Firefox Synchronisation Extension” for the same problem (yes, it has been installed just by Nokia), here in the same position of the regedit, remove also the key named

{A27F3FEF-1113-4cfb-A032-8E12D7D8EE70}

that has the value

C:\Program Files\Nokia\Nokia Ovi Suite\Connectors\Bookmarks Connector\FirefoxExtension\

SOURCE:
How to remove PC Sync 2 Synchronisation Extension