WordPress MU

Hi

I am using the MU for my site. it is set to make new weblogs in format of http://www.site.com/blog1 , because I could not make it use the format of http://www.blog1.site.blog

However it is fine but it makes my other blogs (out of MU) to be broken. It clears www at the begining and adds an extra name at the end of url, so if the blog is http://www.blog2.site.com it changes to http://blog2.site.com/blog2 by this the blog is not working properly, images, css files, search and posts are not showing.

Any solution?
please