popup virker ikke i IE6 under xp men fint under win98 ?

popup virker ikke i IE6 under xp men fint under win98 ?
Hvad kan det mon være?
Dette script åbner et vindue som kaldes fra en flash film:
Flash film script:
on(press){
    getURL("java script:launchwin('contact.htm', 'newwindow', 'height=490,width=356')");
}

Html siden:

<SCRIPT LANGUAGE="JavaScript">

var newwin;

function launchwin(winurl,winname,winfeatures)
{

    //This launches a new window and then

    //focuses it if window.focus() is supported.

    newwin = window.open(winurl,winname,winfeatures);

    if(javascript_version > 1.0)

    {

        //delay a bit here because IE4 encounters errors

        //when trying to focus a recently opened window

        setTimeout('newwin.focus();',250);

    }

}

</SCRIPT>