Internet Explorer hangs when editing Wiki in enlarged editor (fullscreen)

When editing a wiki (1.x) using Internet Explorer, if you click "Enlarge Editor", a new window opens but hangs on loading. See this discussion:

http://moodle.org/mod/forum/discuss.php?d=100728

Steps to reproduce:

1. Using Internet Explorer, add a "Wiki" resource, and fill out the form
2. Click "Save and display"
3. Click the "Enlarge Editor" icon

Expected result:

The HTMLArea editor should open in a new window

Actual result:

A new window opens, but never finishes loading. iexplore.exe must be killed.

As the discussion indicates, there appears to be something wrong with /yui/event/event-min.js. The problem does not occur in Moodle 1.8, so it appears to be a regression in Moodle 1.9. The attached patch implements a workaround, which prevents the "event" library from loading in the HTMLArea.

I imagine this will be a pig to fix, as the YUI library is fairly involved.

Tagged "Major" as it causes a browser crash.