Focusing not work when CKEditor deep in frame in IE6, IE8

[xt21]

1. put the attached files in samples directory
2. start IE8 and open frame0.html
3. highlight the text, for e.g. 456 in top frame and control-c to copy
4. double click a word in second paragraph in the editor to highlight a word (mouse drag to select some text also has this issue) (Note, don't single click on editor or elsewhere after step3
5. control-v to paste

Expected to replace the selected word with clipboard 456, but the text is inserted in the beginning.

[xt21]

FCKEditor 2.6.10 also has this similar problem. But the behavior is more strange, control-v in step 5 will paste to the readonly textbox in the top frame.

[Jakub Ś]

I think there are couple of errors here that cumulate.

1. frameset is not supported in HTML5 -​http://www.w3schools.com/tags/tag_frameset.asp. You should not use frames but rather one single page or iframes instead
2. Pages have only frameset code. There is no doctype, no title which is invalid HTML and puts IE into quirks mode.

Please see attached sample which uses iframe, has doctype and IMO is correct and works.

NOTE: CKEditor 4 doesn't support IE6