Just wanted to point out something that are missed out in the instruction for Multi-Domains plugin.
I was following the instruction, and no matter how accurately I follow the instruction, it still has errors.
Later on I found out that oddly the wp-config.php preset is
define( 'SUBDOMAIN_INSTALL', false);
I change it to true and everything works.
And also, I found out that if you are logged when you rewrite the wp-config.php file (with subdomain=true), you will be forever logged into wordpress and cannot be logged out.
So I think the instruction may want to include log out before changing the wp-config.php file.