BTW: I was able to add this CSS3 code to achieve rounded corners and so far, with the exception of IE7, adding the code below to the input CSS seems to work just fine.
input[type=submit] {
background-color:#25408E;
border:0;
color:#FFFFFF;
font-family:"Arial, Helvetica, sans-serif;
text-align:center;
width:140px;
height:33px;
font-size:12px;
font-weight:bold;
-moz-border-radius: 5px;
-webkit-border-radius: 5px;
}