IE error - Object does not support this property or method

Hi

I try CKEditor 3.1 in my web application. When I run application in IE8, I get this error:
Line 23
Character 1050
Object does not support this property or method

FF, Chrome, Opera works OK.
Samples which are include in folder _samples works in IE OK. So probably is something in my application, but really dont know what.

To fix this problem I had to comment peace of code in ckeditor.js in line 23 from character 1050 to 1180. This code:

/*
if(!z.$.submit.nodeName)z.$.submit=e.override(z.$.submit,function(B){return function(){x.updateElement();if(B.apply)B.apply(this,arguments);else B();};});
*/

It seems that editor works without problem but I have no idea what is commented. I dont know what I turn off, with which functionality it is connected.

This is my implementation of ckeditor:

<textarea id="uvod" name="uvod" cols="67" rows="15"></textarea>
<script type="text/javascript">
//<![CDATA[ 
CKEDITOR.replace( 'uvod',{ skin : 'kama', toolbar: 'ES' });
//]]>
</script>

Have anyone some ideas how to fix this IE error without commented code in ckeditor.js?

Thanks

Peter