[BlueOnyx:26044] php shell_exec() or exec() always returns null

[Brent Epp]

Hello,

I've been trying to get this function working for one site on a BX 
system.  I modified the vsite include file with:

     php_admin_value disable_functions 
system,passthru,popen,escapeshellcmd,proc_open,proc_nice,ini_restore

phpinfo() shows it's loading the local value for disable_functions as 
seen in the above line (note the lack of 'exec' and 'shell_exec' listed 
in the value)

I set PHP with mod_ruid and set it to execute as the vsite owner.

shell_exec() and exec() always return null, even executing a simple 
command where permissions shouldn't be an issue, like `ls /tmp`

What am I missing?

Thanks
  - Brent