Problem with Calendar after upgrade to 3.7.2

[BTTF.com]

Recently migrated my entire vBulletin 3.5.3 installation to a brand new server, then upgraded to 3.7.2. Since that time, my calendar doesn't work anymore, and I get the following errors:

Warning: gmmktime() expects parameter 4 to be long, string given in
[path]/calendar.php on line 410

Unable to add cookies, header already sent.
File: /home/bttf.com/public_html/forums/includes/class_core.php
Line: 3243
I also get the following error on my welcome page when a user is not registerer or not logged in:

Welcome to the [ARG:3 UNDEFINED].

vBulletin seems to believe that the first problem is with an add-on and gave a list of suggestions to try. I removed all of my add-ons and removed all Suspect File Versions. Still received the errors. Then I was told to disable my hooks with this command in my config.php file:

define('DISABLE_HOOKS', true);

This removed the problem, however, it also removed my header file. When I removed the code, the problem returned.

Anyone know how to resolve these issues? vBulletin won't touch it since I have add-ons and referred me here. Thanks.