Problem to append new IMG element, wrapped in DIV, in Opera browser

I run into weird problem while testing my script on Opera browser. One of the script tasks, to get thumbs images from youtube, and to put them into <DIV> container. So I do the following:

$ytbID = $ytbURL.match("(.+?)(\/v/)([a-zA-Z0-9_-]{11})+");
$ytbImg = "http://img.youtube.com/vi/"+$ytbID[3]+"/2.jpg";

//building container for youtube image
$(this).before('<div class="youtoobin" align="left"></div>');
$(this).prev(".youtoobin").append('开发者_开发知识库<div class="thumby" style="background-image:url(' + $ytbImg +'); width:120px;height:90px;cursor:pointer;"><img style="margin:31px 38px;" src="/myscripts/mini-play.png"/></div>');

Now the strange thing in Opera, that sometimes it works and sometimes it doesn't, I mean sometimes 'append()' returns null. It worked flawlessly in all other browsers I tested with (FF, Chrome, IE 6,7,8). I just can't get if there is a problem with append() with Opera or with me?

Thanx for help.

Sam

Could be a "timing" issue (the div you append is not ready when you try to insert content into it), what does this give:

var $div = $('<div class="youtoobin" align="left"></div>');
$(this).before($div);
$div.append('<div class="thumby" style="background-image:url(' + $ytbImg +'); width:120px;height:90px;cursor:pointer;"><img style="margin:31px 38px;" src="/myscripts/mini-play.png"/></div>');