Unable to dynamically add jump list tasks to IE9 / Win7 menu

I am able to add "tasks" to a pinned site in IE9 using meta tags eg.

<meta name="msapplication-task" content="name=Twitter;action-uri=http://www.twitter.com;icon-uri=http://a1.twimg.com/a/1301438647/images/favicon.ico" />

But if I try to add new tasks using javascript, they开发者_开发问答 never show up.

function jQuery_ActivateJumplists() {
    var favicon = "http://a1.twimg.com/a/1301438647/images/favicon.ico";
    var externalWindow = null;

    if (window.external.msIsSiteMode()) {
        externalWindow = window.external;
        externalWindow.msSiteModeCreateJumpList("Twitter!");
        externalWindow.msSiteModeAddJumpListItem("Twitter Link", "http://www.twitter.com", favicon);
        externalWindow.msSiteModeShowJumplist();
    }
};

Any suggestions?

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Appears to have been an issue with corrupt cache in windows. Solution is to create and run a .bat with the following contents...

del /F /Q %APPDATA%\Microsoft\Windows\Recent\AutomaticDestinations\*
del /F /Q %APPDATA%\Microsoft\Windows\Recent\CustomDestinations\*