Domain Mapping redirect to new register page

Hello,

I have set up domain mapping in t01.org. It seem works. When I create a sub-domian jameshu.t01.org and map to jameshu.net, it doesn't go to jameshu.t01.org, it come to a new register page. http://t01.org/wp-signup.php?new=jameshu.net

Please give me some help. Thanks!