Price Sorter - Timeout

I am running Zen V1.3.0.2 on a Linux server.
I have about 12,000 products.
After adding my last batch of products I can no longer run the price sorter.
It runs for a while (hour glass) and then just stops with a white screen.
I guess the script is timing out?

I asked host about script timing out and received this reply,
"We can only have the execution time set to 30s globally but you should be able to add "max_execution_time = 90" to a local php.ini file for your directory."

Tried adding this line to index.php in the admin subdir, this did not fix the issue.
Does anyone know whether this is where it should be or in another file?

Any other ideas about how to work around this problem?

https://www.aurora-teamspirit.com

php.ini is a configuration file for php settings, not a zen .php file.

You can also try using set_time_limit ( int seconds) (this you can use in php scripts, if the server settings allow you)

http://www.klaban.torun.pl/help/php/function.set-time-limit.html (the php.net site is not working well atm)

I now have a php.ini file in my admin directory with
"max_execution_time = 90" in it. Not sure when/if this is read or if it ever executes.
And,
In my index.php file in the admin directory:
"@set_time_limit(600);"

Still getting the same timeout. Am I doing this correct?
Is there a way to tell whether I have actually over-ridden any server settings?

Thanks...