javascript jquery cross-browser swfobject

Why does this work on FireFox but not on Safari?

This code shows YouTube video.

<script type="text/javascript">

    var params = { allowScriptAccess: "always" };
    var atts = { id: "myytplayer" };
    swfobject.embedSWF("http://www.youtube.com/v/P5_GlAOCHyE?enablejsapi=1&playerapiid=ytplayer&allowFullScreen=false&autoplay=0&loop=1&autohide=0&border=0&color2=0xCCCCCC", 
                        "ytapiplayer", "480", "270", "8", null, null, params, atts)

    function onYouTubePlayerReady(playerId) {
        ytplayer = document.getElementById("myytplayer");
    }

</script>

This button starts playing the video at 30 seconds position.
It's working fine on FireFox but not on Safari.

Why? and how can I fix this?

<button name="test" onclick="ytplayer.seekTo(30,true)">Start</button>

Solution

On Safari for mac works fine, see the demo.

Check that:

you are using the latest swfobject version 2.2
Flash Player is enabled
if you are using an old version that you have the <head> tag defined: http://code.google.com/p/swfobject/issues/detail?id=222

Demo: http://jsfiddle.net/IrvinDominin/DKCHN/