USPS module suddenly giving error and blank page on checkout

[mc12345678]

The problem started with a blank page on checkout. I narrowed it down to the USPS module.

The store owner says they changed nothing recently. The problem began on November 9.

The store uses Zen Cart v1.3.9h and has not been upgraded. It has some modifications in design, but no modifications to the shipping modules.

The store was originally installed about two years ago (?) via FTP/zc_install and has been working ok since then.

We're running PHP version 5.2.9 and MySQL version 5.0.96

The error I'm getting is:

[11-Nov-2013 16:01:31] PHP Warning:  simplexml_load_string() [<a href='function.simplexml-load-string'>function.simplexml-load-string</a>]: Entity: line 1: parser error : Start tag expected, '&lt;' not found in /home/store/public_html/includes/modules/shipping/usps.php on line 909
[11-Nov-2013 16:01:31] PHP Warning:  simplexml_load_string() [<a href='function.simplexml-load-string'>function.simplexml-load-string</a>]: 27 in /home/store/public_html/includes/modules/shipping/usps.php on line 909
[11-Nov-2013 16:01:31] PHP Warning:  simplexml_load_string() [<a href='function.simplexml-load-string'>function.simplexml-load-string</a>]: ^ in /home/store/public_html/includes/modules/shipping/usps.php on line 909
[11-Nov-2013 16:01:31] PHP Fatal error:  Call to a member function getName() on a non-object in /home/store/public_html/includes/modules/shipping/usps.php on line 915

Any help would be appreciated. I've searched extensively for the answer and am not seeing anything. I've tried updating the module to the latest version and get the same error, just slightly different line numbers. I uninstalled and reinstalled the module.

The store is at http://store.vapeny.com. The module is currently disabled.

I did update to the latest version of the USPS module, but am getting the same error as I did with the old version. The only difference being the line number where the error occurs. Nothing else was changed. I have never updated Zencart because my customizations are not broken out from the main files. Stuff I learned how to do after the fact.

As far as testing after upload, you cleared cookies/cache before testing again or used a computer/device that had not been to the site in a long while? Saw someone else have the same error message (different warnings) that began Nov 8th, they were using an older version of USPS, but when updated resolved issue. :/ hmmm