IE6 was created 11 years ago. Maybe it's just not possible to force it to accomplish what only modern browsers are capable.
http://forum.graphene-theme.com/graphene-support/internet-explorer-problem
sub-menu works just fine in IE8
Post your site's url so people can take a look.
use this code, in IE8, It's OK. but the header image can't show normal in sub page.
I can upload the screensonp image?
#header-menu, #header-menu-wrap {
background: #1e5799 !important; /* Old browsers */
background: -moz-linear-gradient(-45deg, #1e5799 0%, #0b479d 47%, #2989d8 56%, #9cc1f7 100%) !important; /* FF3.6+ */
background: -webkit-gradient(linear, left top, right bottom, color-stop(0%,#1e5799), color-stop(47%,#0b479d), color-stop(56%,#2989d8), color-stop(100%,#9cc1f7)) !important; /* Chrome,Safari4+ */
background: -webkit-linear-gradient(-45deg, #1e5799 0%,#0b479d 47%,#2989d8 56%,#9cc1f7 100%) !important; /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(-45deg, #1e5799 0%,#0b479d 47%,#2989d8 56%,#9cc1f7 100%) !important; /* Opera 11.10+ */
background: -ms-linear-gradient(-45deg, #1e5799 0%,#0b479d 47%,#2989d8 56%,#9cc1f7 100%) !important; /* IE10+ */
background: linear-gradient(-45deg, #1e5799 0%,#0b479d 47%,#2989d8 56%,#9cc1f7 100%) !important; /* W3C */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#1e5799', endColorstr='#9cc1f7',GradientType=1 ) !important; /* IE6-9 fallback on horizontal gradient */
}