Dear Matt,
Sorry for the frustration. I completely understand that you are frustrated that the plugin doeis nothing in the Joomlas not appear to work as expected. I am frustrated, too, because I simply cannot find the cause of the problem.
1) I cannot reproduce your problem on any of my test installations, even though I tried up and down. I have several stock VM installations (without any other third-party plugins, though).
2) Those warnings are internal PHP warnings that should never appear on the HTML cart page, but rather in the webserver's log file. Actually, AFAICS, there is nothing in the Joomla or VirtueMart code that would include the PHP warnings on the HTML page. So, there seems to be something special about your Joomla template or your VM cart module that includes internal PHP warnings in the HTML output. It is definitely not the default behaviour of Joomla and VM, so I can't help you here, either, because I am not able to reproduce this problems on my machines, either.
Previously, I was of the impression that you explicitly enabled a feature in your template and that you explicitly wanted those warnings to appear. That's why I focused on the cause of the warnings (which I don't understand, because the code explicitly checks whether the country is valis, so the database query for the country details should always return a valid country object) without success so far.
As I said, I have been able to get the warnings when trying to post an order on your machine, but I have not been able to reproduce the two problems (the warnings themselves, and the fact that they are printed on the HTML page rather than the server logs) on any of my installations with the stock Joomla and virtuemart components.
Actually, this (and the second item above) makes me think whether the problem might even be due to some interference between another component/module that you use and my plugin.
Currently, I really don't see any way how to debug such a problem, which I cannot reproduce and which should not appear as far as I understand the code. I will be able to fix the problem as soon as I'm able to reproduce the problem on a machine where I have access to the database and the server logs and where I can insert debug statements into the plugin code to track down why and where the checks go wrong.
As I said, I have tried to reproduce the problem on e.g.
demo.kainhofer.com, but there I don't get any warnings at all. And the warnings in Joomla and Virtuemart are never inserted into the HTML, but are written to the webserver log, so I cannot tell you how to disable them, because I have no idea why they are inserted into the HTML page on your site...
Reinhold
PS: As you notices yourself, those warnings do not break the working of the plugin. Also, normally, they will only end up in the webserver log, so for any other user such warnings are not a big problem, because the buyers will (and should) never see them.
