Logic fails

I have the following code:

<?php if(($time_now<$str) && (($post->register=="0") || ($close_reg<$time_now))) {
                 echo $online_reg_closed_message;
                 } else if(($str<$time_now) && (($row->register=="0") || ($auto_close_reg<$time_now))) {
                 echo $reg_closed_message;
                 } else {
                 echo $final_message;
                 } ?>

$auto_close_reg

84340

$time_now

70164 (at the time of testing, at any rate)

$str

66400

$close_reg

16000

$post->register

0

Now, if the logic is functioning correctly I should (at the time of testing) be seeing the message stored in$reg_closed_message displayed. I'm not. I'm seeing $final_message.

It's probably something obvious but I can't see it. What did I do wrong here?

Thank you.