--------
PS:
没想到在一个blogbus.com的站点通过了Trackback！

顺便粘贴一下我的一些测试反馈：

blog.csdn.net
<?xml version="1.0" encoding="utf-8"?>
<response>
  <error>1</error>
  <message>未将对象引用设置到对象的实例?</message>
</response>

MSN Spaces:
<?xml version="1.0" encoding="iso-8859-1"?><response><error>4</error><message>Blog does not allow Trackbacks</message></response>

Mon Dec 12 22:54:35 CST 2005
http://www.yculblog.com/trackback/0/999501

<?xml version="1.0" encoding="iso-8859-1"?>
<response>
<error>1</error>
<message>Need id</message>
</response>

Mon Dec 12 23:08:42 CST 2005
http://herock.net/cgi-bin/mt-tb.cgi/152
<?xml version="1.0" encoding="iso-8859-1"?>
<response>
<error>0</error>
</response>

Mon Dec 12 23:24:15 CST 2005
http://www.blogbus.com/public/tb.php/1646630
<?xml version="1.0" encoding="iso-8859-1"?>
<response>
<error>0</error>
</response>