If you open a support case, I would be happy to share the page. I do not like to post whole pages from live sites in the forum.
There seems to be some confusion, though. I started out trying to figure out why the condition didn't work, then I saw that no logging would occur, then I dumped the values to check:
<?php if ($test_mode) { // IF IN TEST MODE, DISPLAY DEBUG DATA ?>
<div style="border:solid 1px #FFFFFF; margin:10px; background-color:#FFFFFF; color:#000000;">SESSION:<pre><?php print_r($_SESSION); ?></pre></div>
<div style="border:solid 1px #FFFFFF; margin:10px; background-color:#FFFFFF; color:#000000;">POST:<pre><?php print_r($_POST); ?></pre></div>
<div style="border:solid 1px #FFFFFF; margin:10px; background-color:#FFFFFF; color:#000000;">GET:<pre><?php print_r($_GET); ?></pre></div>
<?php } ?>
The output is long, so I only posted a portion of the dump. The portion of the dump I posted shows the variables are created but have no value.