Illegal string

Hello,
I have a form (form A) with a redirect (to form B). In the extra parameters of the redirect I have the following:

region=location.region
site=location.site

In form B I have a db read with the following condition:

<?php
return array('regions.region_id' => $_GET["region"]);
?>

I also have another db read with the following condition:

<?php
return array('site.site_id' => $_GET["site"]);
?>

Yet I get a warning for the second db read and not the first as seen in the picture:
[attachment=0]Illegal string 1.jpg[/attachment]
I noticed that the $_GET statement is sending the "site" as a string. I've tried casting the variable using the following in the db reader:

<?php
return array('site.site_id' => (int)$_GET["site"]);
?>

but I get the same warning.
Why am I getting this? Is there anyway to correct this besides turning my site Error Reporting down from Simple to None?

Thanks for your help,
Chris