Guarda ho fatto le prove per bene e così ti garantisco funziona con tutti i browser
codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Documento senza titolo</title>
<style type="text/css">
<!--
.over {
	border: 4px solid #000000;
}
.over:hover {
	border: 4px solid #FF0000
}
-->
</style>
</head>

<body>

[img]ddd.JPG[/img]

</body>
</html>