help!! css hover effect compatability

[jlbantang]

<style type=text/css>

ul.itemmenu{
	padding:			0;
	margin:				0;

	list-style:			none;				/*remove the bullets points*/
	background-color: 	#FFFFFF;			/*make container background color white*/
	width:				200px;				/*set list container to fix width*/
	border:				1px solid;			/*make container border visible*/

	font-family:		tahoma;
	font-size: 			0.8em;
	
	text-align:			center;				/*makes menu align horizontally*/			
}

/*apply exclusive hyperlink list formatting to the itemmenu class.
any hyperlink declared outside the itemmenu class
will render unformatted*/

ul.itemmenu li a{
	text-decoration:	none;				/*remove hyperlink underline formatting*/
	display:			block;				/*make list clickable in any list portion*/
	width:				180px;				/*set the display block width*/
	/*padding:			2px 10px;*/
	/*float:left;*/
}

ul.itemmenu li a:hover{
	background-color:	#B9BB79;			/*change hovered list background color to emphasize*/
	border:				1px dotted;			/*and set its border to dotted lines*/
	}

ul.itemmenu li a:active{
	font-weight:		bold;				/*make the selected link bold*/
}

</style>

how to fix this:



make the block line same in all browser