One thing for you to be aware of... it's possible to have multiple versions of PHP installed on a server, each with their own php.ini. It's possible your developer made a change to the PHP.ini file, but the question was it the RIGHT one.
If you check your ACP's support section, there is a section for phpinfo which will show a lot of environmental data:
www.yourdomain.com/admin/?app=core&module=support&controller=phpinfo
In this case, look at "Loaded Configuration File". That's the version being used by your instance.
You can also create a test PHP script that will output what your server is reporting as disabled...
Create a file (like test.php) with the following contents:
<?php
echo ini_get('disable_functions');
?>
The output should list all of the disabled modules and should look something like:
exec, system, passthru, popen, proc_open, shell_exec