at first, the png images will load, then disappear in IE9.
not quite sure.
thanks.
UPDATE. i have mod_pagespeed enabled, which seems to be related to the issue. i disabled the plugin, and the issue was resolved. any way to have it enabled, and have images display as they should?
This sounds like a mod_pagespeed bug. Please submit a bug-report here: https://code.google.com/p/modpagespeed/issues/list
But a temporary work-around is to use ModPagespeedDisallow for these images.