Screenshot IE6 with error dialog open

WikiEditor does a little browser detection to automatically fall back to the classic toolbar when on some known-broken browsers like IE 6.

Unfortunately it looks like something in the behavior for the toolbar buttons doesn't get fully left alone; when clicking any of the buttons (bold, nowiki, etc) in this mode I get a JS error:

'$iframe' is null or not an object

Disabling the WikiEditor extension, this doesn't happen.

Tested on prototype r82004 and trunk r82002

Version: unspecified
Severity: normal
URL: http://prototype.wikimedia.org/rc-en/index.php?title=New_Zealand&action=edit

Attached: