[jQuery] 1.4.1 bug? jwysiwyg uncaught exception

jquery-1.4.1
Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.7) Gecko/20100106
Ubuntu/9.10 (karmic) Firefox/3.5.7

Using Scott Storborg's fork of jwysiwyg [1], when loading a form
through $.ajax() the editor area cannot get focus. If I open the
"source" pane and type in there, once I then close the pane, the text
will appear inside the editor. However, I cannot do anything with the
text. It seems that all keydown events are ignored.

The script that is returned by the AJAX call is:

$(function() {$('#CommentBody').wysiwyg({
controls: {
// lots of key: val pairs ...
}
});

If I click on one of the buttons, I get the following error:

uncaught exception: [Exception... "Component returned failure code:
0x80004005 (NS_ERROR_FAILURE) [nsIDOMNSHTMLDocument.execCommand]"
nsresult: "0x80004005 (NS_ERROR_FAILURE)" location: "JS frame ::
http://mi_mtl.apollo/js/lib/jquery.wysiwyg.storborg.js :: anonymous ::
line 595" data: no]

anonymous(form#CommentAddForm add, "handle", Object
name=data)jquery-1.4.1.js (line 1020)
anonymous(form#CommentAddForm add, "submit", function(), Object
name=data)jquery-1.4.1.js (line 1572)
anonymous()jquery-1.4.1.js (line 2331)
anonymous([form#CommentAddForm add selector=form context=document],
function(), Object name=args)jquery-1.4.1.js (line 572)
anonymous(function(), Object name=args)jquery-1.4.1.js (line 240)
anonymous("submit", Object name=data, function())jquery-1.4.1.js (line 2330)
anonymous(function())jquery-1.4.1.js (line 2495)
anonymous(textarea#CommentBody, Object)jquery.w...orborg.js (line 428)
Wysiwyg(textarea#CommentBody, Object)jquery.w...orborg.js (line 110)
Wysiwyg(textarea#CommentBody, Object)jquery.w...orborg.js (line 111)
anonymous()jquery.w...orborg.js (line 103)
anonymous([textarea#CommentBody length=1 0=textarea#CommentBody
context=document], function(), Object name=args)jquery-1.4.1.js (line
572)
anonymous(function(), Object name=args)jquery-1.4.1.js (line 240)
anonymous(Object)jquery.w...orborg.js (line 101)
anonymous()language:en (line 41)
anonymous(function())jquery-1.4.1.js (line 250)
anonymous(function(), Object name=context)jquery-1.4.1.js (line 160)
anonymous(function(), Object name=context)

If I add some text through the source pane, select it, and then click
the bold button, I get this:

uncaught exception: [Exception... "Component returned failure code:
0x80004005 (NS_ERROR_FAILURE) [nsIDOMNSHTMLDocument.execCommand]"
nsresult: "0x80004005 (NS_ERROR_FAILURE)" location: "JS frame ::
http://mi_mtl.apollo/js/lib/jquery.wysiwyg.storborg.js :: anonymous ::
line 595" data: no]

anonymous(html, "handle", Object name=data)jquery-1.4.1.js (line 1020)
anonymous(Object type=focus timeStamp=1264904061090, [Object
type=focus timeStamp=1264904061090 0=Object], html)jquery-1.4.1.js
(line 1805)
anonymous(Object type=focus timeStamp=1264904061090, [Object
type=focus timeStamp=1264904061090 0=Object], body)jquery-1.4.1.js
(line 1824)
anonymous()jquery-1.4.1.js (line 2352)
anonymous([body 0=body context=body length=1 jquery=1.4.1],
function(), Object name=args)jquery-1.4.1.js (line 572)
anonymous(function(), Object name=args)jquery-1.4.1.js (line 240)
anonymous("focus", Object name=data)jquery-1.4.1.js (line 2351)
anonymous(Object name=fn)jquery-1.4.1.js (line 2495)
anonymous()jquery.w...orborg.js (line 491)
anonymous(Object originalEvent=Event focus type=focus)jquery-1.4.1.js
(line 1884)
anonymous()jquery-1.4.1.js (line 1579)

When I load the editor in a plain page (no AJAX) all is good. I
suspect this may be a jQuery bug with the way it runs script returned
by ajax(). Can anyone shed some light?

Starting in safe mode gave the same error. It works fine in Opera, btw.

[1] http://github.com/storborg/jwysiwyg