Problemas con estilos en Fire Fox

[humanista]

Código CSS:

.tdbook a{ font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12px; color: #3B5998; text-decoration: none; display: block; background-color: #F9F9F9; height: 100%; width: 100%;}
.tdbook a:hover { color: #FFFFFF; background-color: #697FAE; }
 

Código HTML:

<table border="0" cellpadding="0" cellspacing="0">
                    <tr>
                        <td width="247">
                        <table border=0 cellpadding=0 cellspacing=0><tr height=25><td height=25></td></tr></table><table border=0 cellpadding=0 cellspacing=0 bgcolor=#697FAE style='border:solid 1px #CCCCCC;'><tr><td width=500 height=25 valign=middle style='vertical-align:middle;'><table border=0 cellpadding=0 cellspacing=0><tr width=500><td width=500 style='vertical-align: middle;'><a class=ver12bla href=mylibrary.php style='vertical-align:middle;'><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td width=10></td><td height=25>Mi Biblioteca</td><td width=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table></a></td></tr></table></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr height=5><td height=5></td></tr></table><table border=0 cellpadding=0 cellspacing=0 bgcolor=#F9F9F9 style='border:solid 1px #CCCCCC;'><tr><td width=500 height=25 valign=middle style='vertical-align:middle;'><div class=tdbook><table border=0 cellpadding=0 cellspacing=0><tr width=500><td width=500 style='vertical-align: middle;'><a href=myallbooks.php style='vertical-align:middle;'><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td width=10></td><td height=25>Ordenado por libros</td><td width=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table></a></td></tr></table></div></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr height=15><td height=15></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr height=5><td height=5></td></tr></table><table border=0 cellpadding=0 cellspacing=0 bgcolor=#F9F9F9 style='border:solid 1px #CCCCCC;'><tr><td width=500 height=25 valign=middle style='vertical-align:middle;'><div class=tdbook><table border=0 cellpadding=0 cellspacing=0><tr width=500><td width=500 style='vertical-align: middle;'><a href=mybook.php?idrss=51 style='vertical-align:middle;'><img src=http://profile.ak.fbcdn.net/hprofile-ak-snc4/276506_108157165879715_7211445_n.jpg width=25 height=25 border=0 style='margin-left:10px; margin-top:10px; margin-bottom:10px; float:left; vertical-align:middle;'><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td width=10></td><td height=25>El Blog de Enrique Dans</td><td width=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table></a></td></tr></table></div></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr height=5><td height=5></td></tr></table><table border=0 cellpadding=0 cellspacing=0 bgcolor=#F9F9F9 style='border:solid 1px #CCCCCC;'><tr><td width=500 height=25 valign=middle style='vertical-align:middle;'><div class=tdbook><table border=0 cellpadding=0 cellspacing=0><tr width=500><td width=500 style='vertical-align: middle;'><a href=mybook.php?idrss=275 style='vertical-align:middle;'><img src=http://a2.twimg.com/profile_images/1603857291/jm_reasonably_small.jpg width=25 height=25 border=0 style='margin-left:10px; margin-top:10px; margin-bottom:10px; float:left; vertical-align:middle;'><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td width=10></td><td height=25>El Blog de Juan Merodio</td><td width=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table></a></td></tr></table></div></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr height=5><td height=5></td></tr></table><table border=0 cellpadding=0 cellspacing=0 bgcolor=#F9F9F9 style='border:solid 1px #CCCCCC;'><tr><td width=500 height=25 valign=middle style='vertical-align:middle;'><div class=tdbook><table border=0 cellpadding=0 cellspacing=0><tr width=500><td width=500 style='vertical-align: middle;'><a href=mybook.php?idrss=100 style='vertical-align:middle;'><img src=http://profile.ak.fbcdn.net/hprofile-ak-snc4/71136_134020399988488_5035134_n.jpg width=25 height=25 border=0 style='margin-left:10px; margin-top:10px; margin-bottom:10px; float:left; vertical-align:middle;'><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td width=10></td><td height=25>Error500 - Tecnología + Internet + Conocimiento</td><td width=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table></a></td></tr></table></div></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr height=5><td height=5></td></tr></table><table border=0 cellpadding=0 cellspacing=0 bgcolor=#F9F9F9 style='border:solid 1px #CCCCCC;'><tr><td width=500 height=25 valign=middle style='vertical-align:middle;'><div class=tdbook><table border=0 cellpadding=0 cellspacing=0><tr width=500><td width=500 style='vertical-align: middle;'><a href=mybook.php?idrss=97 style='vertical-align:middle;'><img src=http://profile.ak.fbcdn.net/hprofile-ak-snc4/27540_386366515398_96_n.jpg width=25 height=25 border=0 style='margin-left:10px; margin-top:10px; margin-bottom:10px; float:left; vertical-align:middle;'><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td width=10></td><td height=25>ALT1040</td><td width=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table></a></td></tr></table></div></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr height=5><td height=5></td></tr></table><table border=0 cellpadding=0 cellspacing=0 bgcolor=#F9F9F9 style='border:solid 1px #CCCCCC;'><tr><td width=500 height=25 valign=middle style='vertical-align:middle;'><div class=tdbook><table border=0 cellpadding=0 cellspacing=0><tr width=500><td width=500 style='vertical-align: middle;'><a href=mybook.php?idrss=459 style='vertical-align:middle;'><img src=http://a2.twimg.com/profile_images/94488282/logo_cuadrado_reasonably_small.jpg width=25 height=25 border=0 style='margin-left:10px; margin-top:10px; margin-bottom:10px; float:left; vertical-align:middle;'><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td width=10></td><td height=25>Pixel y Dixel</td><td width=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table></a></td></tr></table></div></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr height=5><td height=5></td></tr></table><table border=0 cellpadding=0 cellspacing=0 bgcolor=#F9F9F9 style='border:solid 1px #CCCCCC;'><tr><td width=500 height=25 valign=middle style='vertical-align:middle;'><div class=tdbook><table border=0 cellpadding=0 cellspacing=0><tr width=500><td width=500 style='vertical-align: middle;'><a href=mybook.php?idrss=453 style='vertical-align:middle;'><img src=http://www.optimismodigital.com/wp-content/themes/optimismodigital/images/optimismodigital.png width=25 height=25 border=0 style='margin-left:10px; margin-top:10px; margin-bottom:10px; float:left; vertical-align:middle;'><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td width=10></td><td height=25>Optimismo Digital</td><td width=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table></a></td></tr></table></div></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr height=5><td height=5></td></tr></table><table border=0 cellpadding=0 cellspacing=0 bgcolor=#F9F9F9 style='border:solid 1px #CCCCCC;'><tr><td width=500 height=25 valign=middle style='vertical-align:middle;'><div class=tdbook><table border=0 cellpadding=0 cellspacing=0><tr width=500><td width=500 style='vertical-align: middle;'><a href=mybook.php?idrss=458 style='vertical-align:middle;'><img src=http://profile.ak.fbcdn.net/hprofile-ak-ash2/50496_8370633305_6491_n.jpg width=25 height=25 border=0 style='margin-left:10px; margin-top:10px; margin-bottom:10px; float:left; vertical-align:middle;'><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td width=10></td><td height=25>Loogic.com</td><td width=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table></a></td></tr></table></div></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr height=5><td height=5></td></tr></table><table border=0 cellpadding=0 cellspacing=0 bgcolor=#F9F9F9 style='border:solid 1px #CCCCCC;'><tr><td width=500 height=25 valign=middle style='vertical-align:middle;'><div class=tdbook><table border=0 cellpadding=0 cellspacing=0><tr width=500><td width=500 style='vertical-align: middle;'><a href=mybook.php?idrss=49 style='vertical-align:middle;'><img src=http://profile.ak.fbcdn.net/hprofile-ak-ash2/41786_41267802635_7202_n.jpg width=25 height=25 border=0 style='margin-left:10px; margin-top:10px; margin-bottom:10px; float:left; vertical-align:middle;'><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td width=10></td><td height=25>Xataka</td><td width=10></td></tr></table><table border=0 cellpadding=0 cellspacing=0><tr><td height=10></td></tr></table></a></td></tr></table></div></td></tr></table>                      </td>
 
                    </tr>
                </table>