phpSuExec (pronounced sue-eksek) is a more secure environment for PHP. All of our shared servers are phpSuExec. Most dedicated are as well.
This secure environment makes 777 file permissions unacceptable, and makes php.ini necessary.
To verify your server is using phpsuexec, create a simple 'php info' script.
Create a file named 'phpinfo.php' in the public_html folder of your site and insert the following code:
phpinfo();
?>
?>
Load the file in your browser and in the top section find the line 'Server API'.
If it shows 'CGI' then your account is on a server with phpsuexec.
If it shows 'apache' then you are NOT on a phpsuexec server.
Now you also know if PHP is running as Apache or CGI.