IE9 JS error sometimes when clicking disabled editor area

Hi.

I have a situation where I get a JS error quite consistently. The error originates from selection\plugin.js, around line 487.

What I do beforehand is in some situations I clear the contents of the editor and then disable it. I'm using IE9, the code below outputs debug saying that the value of ownerDocument cannot be gotten, the object is null or undefined.

try {
   if (sel.type != 'None' && range.parentElement().ownerDocument == doc.$) {
      range.select();
   }
} catch (err) {
   if (typeof (debug) !== 'undefined') {
      debug('selectionChange threw an error');
      debug(err);
   }
}

How I disable the editor:

// in one function
editor.setData('', function () {
   editor.updateElement();
});

// then, in another function after some other things
ckeditor.setReadOnly();