you can rename the file and see if the site is working.
are you sure the permissions of the /var/www/virtual/domain.tld/... structure are correct?
Code:
# ls -la /var/www/virtual/domain.tld/
insgesamt 40
drwxrwx--- 8 vu2002 www-data 4096 2008-03-01 03:00 .
drwxr-xr-x 9 vu2000 www-data 4096 2008-02-20 23:14 ..
drwxrwx--- 2 vu2002 www-data 4096 2008-03-01 03:00 backups
drwxr-xr-x 2 vu2002 vu2002 4096 2007-09-08 11:01 cgi-bin
drwxrwxr-x 2 vu2002 vu2002 4096 2007-09-08 11:01 errors
drwxrwxr-x 3 vu2002 vu2002 4096 2008-01-31 12:28 htdocs
-rw-r----- 1 vu2002 www-data 1 2007-09-08 11:01 .htgroup
-rw-r----- 1 vu2002 www-data 1 2007-09-08 11:01 .htpasswd
drwxrwx--- 2 vu2002 www-data 4096 2007-09-08 23:30 logs
drwxrwx--- 2 vu2002 www-data 4096 2007-09-08 11:01 phptmp