Please help! error reading data from FastCGI server

[xciso]

Hello.
I have a VPS server thats running ispconfig 3.
It has worked great for soon 2 years, but now I have a big problem.

I have a webshop that i installed a new extension too last night.
The extension shell do a XML file like pricerunner, (prisjakt.se)

The first thing is that the extension is verry memory hungry.
I have now set in /etc/php5/cgi/php.ini:

memory_limit	2048M

max_execution_time	180

If I dont do this I get errors for it. I dont understand how this can process 2048mb.
Now i get error 500.
Url too the file i will show is: www.bjarud.se/index.php?route=feed/prisjaktprice

When i look at the logs i get theese error now:

(104)Connection reset by peer: mod_fcgid: error reading data from FastCGI server
Premature end of script headers: index.php

Please help!