Comment: web address != to physical directory, install problem

gah... this is hopeless... YACS isn't designed to run on a subdomain.

You use $_SERVER['SERVER_NAME'] everywhere. As I established above that isn't a variable one should use, since its not always accurate.

Quoted from PHP manual:

" 'HTTP_HOST'

Contents of the Host: header from the current request, if there is one. "

If this variable exists it should always be used over 'SERVER_NAME'.