Please accept my apologies for letting it show.
Dude, don't apologize. You're doing this for free. I'm amazed at your efforts as it is.



This is a maybe. IF you are getting a blank page because your data and shipping methods cannot provide a legitimate/valid quote you'll need to alter your settings to emulate the old behaviour (untick the 'hide letter rates if parcel sized), or, you can enable letters as a valid shipping method, or you can provide accurate weights and dimensions to your products and obtain accurate quotes.

However, if you are getting the blank page because the server can't be contacted (possibly because your ISP doesn't have cURL installed (unlikely) , or that they use a proxy server for cURL requests (possible), then you'll need to need to define your proxy settings located under the zencart configuration/myStore settings.

Sadly the hide letter rates were already set to NO. My server curl info is shown below.
cURL support enabled
cURL Information libcurl/7.18.2 OpenSSL/0.9.8g zlib/1.2.3.3 libidn/1.8 libssh2/0.18

Still a blank page.
I don't think its a curl issue. Or an issue with sizes and weights as the estimate shipping page works every time. How is the estimate shipping page different from the proceed through to checkout page?

This is what I know so far. That the estimate shipping page works every time. That sometimes when I do a refresh of the blank page the actual shipping information comes through. Or ar least some of the rates comes through as I noticed one time that the ECI costings were missing.

That if I run the same module with the same settings from my zencart 1.3.7 installation (which I no longer use) that it works every time. I'm currently using the 1.3.8 zencart version.

I had trouble first setting up my 1.3.8 installation as my host uses shared sessions. I had do set up a special session path in my configuration.php files to get 1.3.8 to install properly. I'm wondering if thats significant.

Enabling the debug mode returns information indicating that the mail server responded ok, with no errors apparent.

I'm wondering if this has anything to do with my Shared SSL certificate as the url on the blank page seems to access the secure page address. My 1.3.7 version zencart doesn't have SSL enabled.