Internet Explorer 8 on Windows XP specific flavor of bug #64093 (but apparently also present on IE6, but I wouldn't know, as I can't be bothered to test anything on IE6).
Version: 1.23rc
Severity: normal
Platform: PC
URL: https://www.mediawiki.org/
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=64093