Problem about admin url

[urnice]

i installed prestashop under the directory of my blog site, and set a domain to the folder.

Then my web store has a domain and a subdomain. The domain is http://www.mineralcrystalonline.com, the subdomain is mineralcrystalonline.MUBLOGDOMAIN.com.


The problem is i can enter my site with the domain, but when i tried to enter the back office, the admin url would automaticly point to mineralcrystalonline.MUBLOGDOMAIN.com.


It does not affect any use of back office, but when i generated a google sitemap, all the urls in it are mineralcrystalonline.MUBLOGDOMAIN.com/xxxx.html, but not http://www.mineralcrystalonli.com/xxxx/html


I wonder what's the problem and how to resolve it. I think there should be a config file to set the path of back office, but can't find it.
Could someone help me? Thanks!