There might be a fix to <input type="button"> - but if there is, I don't know it.
Otherwise, a good option seems to be to replace it with a carefully styled a element.
Example: http://jsfiddle.net/Uka5v/
.button {
background-color: #E3E1B8;
padding: 2px 4px;
font: 13px sans-serif;
text-decoration: none;
border: 1px solid #000;
border-color: #aaa #444 #444 #aaa;
color: #000
}
Upsides include that the a element will style consistently between different (older) versions of Internet Explorer without any extra work, and I think my link looks nicer than that button :)