Currently there's no gradient at all at the top of the page, because the gradient mixin is missing the filter for gradient support in IE6-9.
It'd be something messy like this:
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='@startColor', endColorstr='@endColor',GradientType=0 );
More on this later when I can feel my hands.
Version: 1.23.0
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=61010