Problems with new site in ISPConfig

I installed everything following The Perfect Server - Ubuntu 10.10 [ISPConfig 3]

I can run phpmyadmin, ISPConfig, everything is OK

I create new client, then login as this client.
Create new site, new ftp user, new database, everything is ok

I can see default page of my site.

But when I upload content of site, I deleted default index.html and put there my index.php
And when I try to open site I get permanent Error 500


This site perfectly works on my local server.

Please, help, what problem maybe?