Shopping Cart - Add to Cart not working, using SEO mod and TM template

[Website Rob]

Have a Client with TM Template (yes, I know) who had 1.3.7 version working fine. Did an upgrade to 1.3.8a and now have this problem.

Choosing a Category you get the Product Listing page.

If you choose "Buy Now" (this uses a URL) it gets added to the Shopping Cart.

If you choose "Details" then "Add to Cart" (this uses Form code), msg. says "Your Shopping Cart is empty".

The above happens with both; logged in and not logged in.

Appears there is something different between using a URL and Form code, for adding to the cart.


Have confirmed files that should have been updated have been and everything else works as it should.

Would anyone know where to look for the answer to this problem?


Edit:
One other thing, this account is with another Hoster and there are some cURL problems.

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CURL requires SSL support. Please notify webmaster or hosting company. 1 => libcurl was built with SSL disabled, https: not supported!

CURL problems detected: 28 => connect() timed out!
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As payments were going through just fine before, not sure if the cURL problem is related to the above problem but mention it for clarification. I've also used the Debug Module/file [enable_error_logging.php] but no errors reported, no log file created.