Internal server error 500 with php files

[kess]

I assume that the interested domain name is "mydomain.com".
As root type what follows using SSH or directly on the server console:
cd /var/www/virtual
chown vu2002:www-data mydomain.com
chmod 770 mydomain.com
cd mydomain.com
chown vu2002:vu2002 htdocs -R
chmod 755 htdocs -R

Try again to browse your pages...
This type mismatch happens generally when you move web pages from one domain to anotherone using SSH...

In order to be sure that this won't happen again, use FTP instead.

Hope this helps.
Bye Kess.