Unlike earlier betas of IE 7, the new beta 2 public release seems to choke on
our workaround for displaying transparent logo PNGs in IE 5.5/6.0. You may find
that the logo is missing altogether when visiting a MediaWiki site using
MonoBook skin with IE 7.
The good news is that IE 7 supports alpha-transparent PNGs natively, so the
workaround isn't needed there; a one-line fix to skins/MonoBook.php will disable
If there's no other surprises found, I'll make bug fix releases for 1.4.15 and
1.5.7 which include this fix in a day or two.