AjaxUploader error in Opera

I'm trying to integrate AjaxUploader into my site, but only in Opera browser I have an error, in other browsers it forks fine Besides, if I testing this code on new test server it forks fine in Opera browser too.

I 开发者_StackOverflow中文版can't understand what's going on, help me please.

Here is the stacktraca from Opera debugger:

    Uncaught exception: ReferenceError: Security error: attempted to read protected variable

Error thrown at line 2216, column 2 in <anonymous function: Sizzle>(query, context, extra, seed) in http://site/assets/js/jquery1.6.js:
    if ( !seed && context.nodeType === 9 && !isXML(context) )
called from line 292, column 3 in <anonymous function: find>(selector) in http://site/assets/js/jquery1.6.js:
    jQuery.find( selector, this[0], ret );
called from line 230, column 4 in <anonymous function: submit>() in http://site/assets/js/ajaxupload.js:
    var response = iframe.contents().find('body').html();
called from line 2693, column 4 in <anonymous function: handle>(event) in http://site/assets/js/jquery1.6.js:
    var ret = handler.apply(this, arguments);
called via Function.prototype.apply() from line 2467, column 4 in <anonymous function: add>() in http://site/assets/js/jquery1.6.js:
    return typeof jQuery !== "undefined" && !jQuery.event.triggered ?

Looks like built-in cross-site scripting attack prevention. In some form or another (are you using iFrames?) you are trying to access a resource on one site from another site in a way that the browser is disallowing.