USPS Shipping Extension issue

I am running a clean install of 1.4.9.1 and am unable to implement the USPS Shipping extension successfully.

I have obtained my USPS Web Tool credentials and had them switch me over to the production server.

When I enable the extension, I get a blank page when progressing to index.php?route=checkout/guest_step_2 during checkout. I don't receive any error messages, just a blank html page generated.

When the extension is uninstalled or disabled, I have no issue and the flat rate shipping method is shown along with what is expected.

Is anyone else having any issues with this extension in 1.4.9.1, or has anyone successfully made this extension work in this version?

Much appreciate anyone's feedback.

Many thanks to fowlrock...installing the php-xml module worked like a champ!

Issue resolved.

See post: http://forum.opencart.com/viewtopic.php?f=114&t=20298

viewtopic.php?f=114&t=20298 talked about UPS not USPS.

I am having the same issue with going to USPS, getting my user id and password via email after filling out their webtools form. Calling Tech support and having them switch my user id from the test server to the production server.

But before calling up USPS tech support to switch servers, I saw the error message about not be Authorized. So the module was showing and giving the proper message. After calling USPS and they switched it, i did a refresh and Hocus Pocus the module was not showing anymore.

Can anyone direct me in the right direction. Is this a code thing on Open Cart side? Because the code seemed to be working fine when the error message was thrown when the user id from USPS was on the test server. But once moved to production, nothing.

Please advice.