Continuo com o mesmo problema, lembrando que já utilizei o :hover em um local, não sei se isso interfere, utilizei ele no menu, na qual funcionou com sucesso...
#menu_titulo ul li a:hover {
-moz-border-radius: 8px;
-webkit-border-radius: 8px;
border-radius: 8px;
background: -moz-linear-gradient( center top, #a8ba21 12%, #779612 93% );
background: -ms-linear-gradient( top, #a8ba21 12%, #779612 93% );
filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#a8ba21', endColorstr='#779612');
background: -webkit-gradient( linear, left top, left bottom, color-stop(12%, #a8ba21), color-stop(93%, #779612) );
background-color: #a8ba21;
color: #ffffff;
display: inline-block;
text-shadow: 0px 0px 0px #ffffff;
-webkit-box-shadow: inset 5px 4px 13px 3px #55690e;
-moz-box-shadow: inset 5px 4px 13px 3px #55690e;
box-shadow: inset 5px 4px 13px 3px #55690e;
position: relative;
right: 10px;
padding-top: 5px;
padding-right: 10px;
padding-bottom: 5px;
padding-left: 10px;
margin-right: -20px;
}