No hover color in IE 9

I am seeing the same issue. Works fine in FF, Safari, Chrome, but not in IE--although the right side navigation works in IE. Any updates?

This filter seemed to be the cause of the grief...I commented it out and it works now in IE

.navigation li.active-trail a,
.navigation li a.active,
.navigation li a:hover,
.navigation li a:focus,
.navigation ul li:hover a {
background: #f2f2f2; /* Old browsers */
background: -moz-linear-gradient(top, #f2f2f2 0%, #ececec 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#f2f2f2), color-stop(100%,#ececec)); /* Chrome,Safari4+ */
background: -webkit-linear-gradient(top, #f2f2f2 0%,#ececec 100%); /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(top, #f2f2f2 0%,#ececec 100%); /* Opera11.10+ */
background: -ms-linear-gradient(top, #f2f2f2 0%,#ececec 100%); /* IE10+ */
/*filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#f2f2f2', endColorstr='#ececec',GradientType=0 ); IE6-9 */
background: linear-gradient(top, #f2f2f2 0%,#ececec 100%); /* W3C */
border-right: 1px solid #FFF;
border-left: 1px solid #FFF;
padding-left: 19px;
padding-right: 19px;
color: #333;
}

/******* Drop-down Navigation ******/