Permission problem after upgrade to 10.04

[gangelies]

Hi everyone
I need some help with my hosting server.
After the upgrade to Ubuntu 10.04 LTS I encountered some problems with directory permission.
As suggested in this post i deactivated PHP global modifying /etc/mime.types and /etc/apache2/mods-enabled/php5.conf, so the permmision was solved but now.... i cannot access to my ISPconfig web interface.
Apache error log says:

SoftException in Application.cpp:221: File "/usr/local/ispconfig/interface/web/index.php" is not in document root of Vhost "/var/www"

Some suggestions?
Thank you in advance

Gangelies